It's not a pretty word, nor an easy idea to grasp.

But it has inspired thousands from Scotland and elsewhere to get on their feet and protest.

This week a trainload of protestors will be heading for Brussels to raise their voices against TTIP - the Transatlantic Trade and Investment Partnership - which is beginning its crucial next round of negotiations.

It's a big business deal between the European Union and the United States that will determine how goods are traded across the world.

According to the protestors, it will do great harm. It will hand multinational corporations unprecedented powers to trash the environment, privatise public services and undermine democratic rights, they warn.

TTIP will reduce barriers to free trade, which companies say will bring economic benefits. But the organisers of this week's protest, Global Justice Now - formerly the World Development Movement - argue it will threaten people and the planet.

TTIP will make it easier for multinationals to sue governments, and could lead to environmental and safety standards being slashed, they say. It could be used to privatise the National Health Service, and will shift the balance of power in favour of the rich and against the poor, they argue.

"Sovereignty is obviously an issue that's very important to Scottish people," said Liz Murray from Global Justice Now Scotland. "So it's no wonder that people are angry at the idea of David Cameron and Brussels handing over enormous amounts of power to multinationals at the expense of our democratic process."

The business lobby, as represented by Confederation of British Industry (CBI), disagrees. It says that TTIP will give an annual £10 billion boost to the UK economy, and increase EU exports to the US by 28 per cent a year.

Campaigners, however, are convinced that the human and environmental costs are too high. A petition against TTIP by 38 Degrees has so far been signed by over 1.3 million people (https://secure.38degrees.org.uk/page/s/eu-ttip-petition#petition).

On Tuesday and Wednesday more than 100 ordinary people from across the UK will be going to Brussels to lobby their MEPs and take part in a Europe-wide rally against TTIP. The Sunday Herald asked some of those who are going - and a business association that isn't - to tell their stories.

WHY WE ARE PROTESTING:

Alistair Heather (25), a history student at Aberdeen University from the village of Newbigging in Angus:

"I'm not an activist. Aside from joining a million other white-clad walkers one day in Edinburgh to make poverty history, I've never protested for or against anything.

"I had read about TTIP in a few newspapers. The concern is that it would create an open portal for American corporate business practises over here. To me, this means lawsuits galore, unreal quantities of corporate greed and tax avoidance.

"The NHS could be at risk. If TTIP were passed then the British state would be open to a lawsuit from American firms, on the basis that it was preventing an open and free market. The NHS is the sole justification of income tax for me, and I need it protected.

"A nationalised train network seems a sensible and achievable goal in this day and age. It is something we could aim for over the next decade. Free trade with America would kill this promising idea stone dead.

"When I'm in Brussels next week I'll be part of a wider movement. People will shout about the environment, people will shout about democracy. I'll be there for the NHS and for the trains."

Sandra Lowe (67), a retired school technician from St Andrews:

"I took no real interest in politics until the referendum, which is when I first heard about TTIP. We formed the St Andrews Town and Gown TTIP action group.

"We are planning to speak to our MEPs about our concerns and to join the demonstration to show that there are many people across Europe who are worried about this trade deal going ahead.

"What concerns me is the lack of transparency and discussion surrounding it. The majority of people in the UK know very little about it or have even heard of it which, considering the implications of TTIP, is quite appalling.

"I don't wish to see a future where international corporations are more powerful than countries, where regulatory barriers are removed so that we have no control over our food standards, environmental regulations, labour rights and banking regulations."

William McGregor (74), a retired farmer from Cupar in Fife:

"A chance encounter with a small group of NHS workers campaigning on a dreich December day at the Cross in Cupar against TTIP impressed me. Their message was simple, our wonderful Scottish health service could be at risk. They got me thinking.

"Big business is behind this, very effectively and professionally lobbying our politicians, convincing them of a wonderful future for all. The reality is big business is only interested in big profits, and market domination. The irresponsible behaviour of some of our major supermarkets towards their suppliers is a disgraceful example and nothing short of bullying.

"These hardy NHS workers, spending their leisure time out on the streets this winter have a very important message and should be listened to."

Ross Mackay (31), an oil industry worker in Aberdeen:

"TTIP really worries me. It's has yet to really pervade the mainstream consciousness, but it's something everyone should be concerned about. There's a lot of secrecy around the treaty, which is alarming.

"The treaty could open up the NHS to further privatisation, and allow big businesses to sue the government if Scottish or British laws dent their profits. TTIP threatens workers' rights, jobs, the environment, public health, public institutions, privacy, openness, accountability, transparency and democracy itself.

"TTIP is not really about opening up trade and harmonising tariffs and regulations; it's about a race to the bottom, locked-in privatisation, and a seismic shift in power away from people and their elected governments towards corporations.

"The Investor State Dispute Settlement provision worries me most - probably the most controversial part of the deal. ISDS could allow corporations like British American Tobacco to sue governments, in secret, supra-national courts, for raising the permitted age of smoking.

"TTIP only offers prosperity for the one per cent, the wealthy elites. We need to show our opposition now before it's too late and the deal goes through. We want the negotiations on TTIP to stop."

Dr Julie Watt (74) and her husband, Richard (75), retired teachers from Edinburgh:

"We are very concerned about TTIP and its potential legacy for our eleven grandchildren. It seeks to promote the now largely discredited neo-con economic agenda, and could relax European controls over environmentally destructive practices.

"It threatens public health services and democratic decision-making by enabling companies to sue governments which make decisions which damage profits. So far negotiations between the US and EU have been cloaked in secrecy.

"As more information has leaked out, alarm bells have been ringing for all who prefer democratic government. TTIP threatens much that we would consider essential to any civilised society."

Nathan Mansfield (34), manager of a visual communication company:

"I discovered TTIP over 18 months ago. I was alarmed at what I read in countless articles that highlighted the intentions of the TTIP agreement and the manner in which these negotiations were taking place. Creating this agreement in secrecy is alarming and calls for an inquiry into those that are pushing this ahead behind closed doors.

"The reason I will be going to Brussels this Wednesday is to show my support for the cancellation of TTIP. I want to help humanity elevate to a better way of living, loving and forgiving ourselves and each other. TTIP is a step in the opposite direction.

"This so called trade agreement is completely non-democratic and only benefits a small minority that already have too much power. Those trying to push TTIP forwards have the money and power to stop poverty, wars, slavery and human trafficking. But they don't.

"I am outraged at more signs of governments privatising public sectors. Health, education and energy sectors should be within the public sector, owned by the country and not a few individuals who reap obscene profits for themselves.

"TTIP represents an unabashed corporate attack on democracy. TTIP will guarantee transnational corporations the right to bid for all government spending, including on health.

"Privatising these public services will reduce government capacity to control the price of medicines and health services. In this way the TTIP could transform our health systems, shifting their focus from caring for the real needs of the people, to making profit for a few elite groups."

David Williamson (40), communications director of the Scotch Whisky Association:

"At the Scottish Parliament I had the opportunity to participate in an often lively debate on the importance of TTIP. It matters to the Scottish economy and scotch but not perhaps in the most obvious of ways.

"The US is scotch whisky's largest market by value, with annual exports of over £800 million. Scotch already benefits from a zero tariff, a reasonable and non-discriminatory excise duty, and robust legal protection. That suggests further EU-US trade liberalisation is likely to deliver only modest direct commercial benefits.

"There are benefits to be gained however. For every customer in the UK, there will be five more in the USA to sell to. The removal of remaining border fees on whisky would save around £4 million a year.

"More significant is the chance to secure improved regulatory coherence, setting globally relevant rules. Industry on both sides of the Atlantic has jointly proposed a spirits annex that has the potential to reduce import costs, complexity and uncertainty.

"Yet there is, frankly, a bigger picture and a long-term view is necessary. An ambitious TTIP would set an important precedent, creating a gold standard for future free trade agreements in markets where trade barriers are more commercially significant.

"TTIP is not the only game in town. The US is negotiating with its partners along the Pacific Rim and a failure to conclude an ambitious TTIP would likely place EU exporters at a competitive disadvantage in relation to these countries.

"As TTIP discussions evolve, it is worth remembering that it is just one part - if an important part - of a wider trade landscape that could have significant implications for growth. At a time when global economic headwinds and geopolitical uncertainties are challenging many Scottish businesses, open markets are vital to Scotland's export potential."