THERESA May’s big pitch for the centre ground of British politics has been overshadowed by a major row over immigration in which the Conservative Government has been branded “vindictive” and “xenophobic”.

The Prime Minister used her first end-of-conference speech to tell Tory activists that “a change is going to come” with a determination to turn Britain into a great meritocracy based on the values of fairness and opportunity.

Mrs May signalled a break from small-state Conservatives such as Margaret Thatcher, insisting government could be a “force for good” by intervening to rein in dysfunctional markets and support key industries.

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And she stressed how Conservatives should value not only wealth creation and success but also a "spirit of citizenship" and a "sense of public service," that respected the bonds and obligations which made society work.

But an earlier suggestion made during the party conference in Birmingham that, as part of the bid to control borders in the Brexit process, companies might have to specify the number of foreign workers they employed caused outrage.

Some likened it to Gordon Brown’s controversial mantra in 2007 of “British jobs for British workers”.

Nicola Sturgeon denounced the Conservative plan to target foreign workers as the “most disgraceful display of reactionary right-wing politics in living memory”.

The First Minister declared: “Theresa May’s vision of Brexit Britain is a deeply ugly one; a country where people are judged not by their ability or their contribution to the common good but by their birthplace or by their passport.

“It is a vision the Scottish Government wants no part of, and one which we will never subscribe to. Ours is a vision of an inclusive, tolerant and just society and we will do everything in our power to shape Scotland in that way,” added Ms Sturgeon.

Kezia Dugdale, the Scottish Labour leader, was equally appalled, suggesting the Tories appeared to be “morphing into Ukip”.

She said: “The chilling suggestion that firms should be forced to reveal how many migrant workers they employ shows just how xenophobic and vindictive the modern Tory Party has become.”

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But in her speech to conference, Ruth Davidson, the Scottish Tory leader, struck a supportive tone on migration, saying: “As we have difficult – but necessary - debates on how we manage borders in future, let us not forget that behind discussions of numbers and rules and criteria, there lies people and homes and families.

“And for those who have already chosen to build a life, open a business, make a contribution, I say this is your home and you are welcome here.”

In light of the controversy, Amber Rudd, the home secretary, who originally flagged up the proposal, began to row back on it, stressing how it was merely part of a “consultation” and was "not something we're definitely going to do".

In her keynote speech, the PM described the Brexit vote in June as "a turning point for our country... a once-in-a-generation chance to change the direction of our nation for good".

She explained that it reflected not just a desire to quit the EU but also expressed a "deep, profound and...justified" sense that the world works for a privileged few but not for ordinary working-class people.

Describing it as a "quiet revolution", the party leader told conference: "It was a vote not just to change Britain's relationship with the European Union but to call for a change in the way our country works - and the people for whom it works - forever."

Acknowledging public frustration over unaffordable housing, stagnating wages, insecure jobs and pay undercut by low-skilled immigrants, she warned: "If we don't respond - if we don't take this opportunity to deliver the change people want - resentments will grow; divisions will become entrenched and that would be a disaster for Britain."

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In a message to well-paid bosses who failed to look after their staff or allow pension funds to go bust, multinationals that dodged tax and tech giants who refused to co-operate with the authorities in the fight against terrorism, Mrs May said: "I'm putting you on warning. This can't go on any more."

She hinted at action against energy companies which put customers on overpriced tariffs and firms which exploited complex pricing structures to inhibit consumer choice. "Where markets are dysfunctional, we should be prepared to intervene," she declared.

The PM hailed the United Kingdom and made clear she would “always fight to preserve our proud, historic Union and will never let divisive Nationalists drive us apart”.

She attacked the so-called liberal elite’s attitude to ordinary working people, saying: “They find their patriotism distasteful, their concerns about immigration parochial, their views about crime illiberal, their attachment to their job security inconvenient. They find the fact that more than seventeen million people voted to leave the European Union simply bewildering.”

Mrs May insisted what she was offering was "a bold plan to bring Britain together; to build a new united Britain, rooted in the centre ground".

She received one of the loudest rounds of applause when she attacked Labour. Having once told conference people regarded the Tories as the nasty party, the PM pointed out how Labour under Jeremy Corbyn was “fighting amongst themselves...tolerating anti-Semitism and supporting voices of hate.” She added: “Do you know what some people call them? The nasty party.”