Brexit Day marks the 'dawn of a new era,' says Boris Johnson, giving Britain a moment of national renewal

Earlier, he will chair a special Brexit Cabinet in Sunderland, a symbolic location for Brexit supporters as it was, three and a half years ago, the first city to declare support for leaving the EU.

This evening, a clock will be projected on the façade of No 10 to countdown to Brexit. Buildings across Whitehall will be illuminated in the Union colours of red, white and blue while Union flags will be flown at Parliament Square and down the Mall.

In his televised address, Mr Johnson will say: “Our job as the Government, my job, is to bring this country together and take us forward. And the most important thing to say tonight is that this is not an end but a beginning.

“This is the moment when the dawn breaks and the curtain goes up on a new act. It is a moment of real national renewal and change,” he will declare.

“This is the dawn of a new era in which we no longer accept that your life chances, your family’s life chances, should depend on which part of the country you grow up in. This is the moment when we begin to unite and level up,” the PM will add.

As Brexit happens, he will host a reception in No 10 for Downing St staff.

While the Brexiteers failed in their campaign to get Big Ben to bong in Brexit, they have organised a mass celebration in Parliament Square. Nigel Farage, the Brexit Party leader, is expected to be there.

Alister Jack said Britain’s departure from the EU tonight was finally honouring the result of the 2016 referendum.

The Scottish Secretary said: “I know that Scotland, and the rest of the UK, will flourish outside of the EU; our coastal communities will leave the hated Common Fisheries Policy, our farmers will benefit from a system of funding that works for them and we will strike lucrative trade deals around the globe, opening up new markets for Scotland’s world class businesses.

“We will take back control of our borders, our laws and our money, allowing us to invest in the ambitious infrastructure projects the UK needs.”

He added: “We will build a stronger economy, creating opportunity and prosperity for everyone. We will move forward together, as one United Kingdom, to a bright future.

“It’s time for Nicola Sturgeon to drop her constant demands for independence and instead work with us to ensure a prosperous future for Scotland.”

Jeremy Corbyn said that Britain from today stood at a crossroads.

“As we leave the EU, we have an opportunity to shape our future role within the international community for decades to come. Britain’s place in the world will change. The question is what direction we now take.

“We can work with other countries to develop trade, improve rights and protections, invest in our communities, tackle the threat of climate catastrophe, fight human rights abuses and promote peace. We can build a truly internationalist, diverse and outward-looking Britain.

“Or we can turn inwards, and trade our principles, rights and standards to secure hastily arranged, one-sided, race-to-the-bottom trade deals with Donald Trump and others.”

Labour, he insisted, would “always want to ensure a close, strong and co-operative relationship with the European Union”.

The Labour leader added: “Whatever side we took in the Brexit debate, we now need to bring the country together to shape our common future, work to rebuild and strengthen our communities, and eliminate poverty and injustice in our society.”

Yesterday afternoon, Mr Johnson visited the Department for Exiting the EU to thank staff for their “hard work”.

He said: “We are leaving the EU and will become an independent country again ready to determine our own future. Some of you would have joined at the beginning of the journey and others more recently but without your combined efforts we would not be where we are today.”

The department ceases to exist from 11pm. Staff have all been promised jobs elsewhere in Government if they want one. Stephen Barclay, the Brexit Secretary, will also be out of a job.

Diplomatic engagement around the trade negotiations will resort to the Foreign Office with the implementation of the Withdrawal Agreement and readiness for the transition period in 2020 overseen by the Cabinet Office.

From Saturday, the Government’s “Task Force Europe,” a team of 40 officials leading the trade negotiations, will be headed by David Frost, the Government’s chief advisor on Europe, who will report directly to the PM.

UKRep or UKMis will become the official UK mission in Brussels while Sir Tim Barrow, Britain’s Permanent Representation in Brussels, will become its ambassador to the EU.

Next week, Mr Johnson is due to give a keynote speech in London looking ahead to the hoped-for trade deal between the UK and the EU.

He has insisted there will be no formal policy of alignment and that post-Brexit Britain would become a rulemaker not a rule taker.

However, Simon Coveney, the Irish Minister for Foreign Affairs, warned that without a "level playing field," there would be no EU trade deal with Britain post-Brexit.

The Tanaiste said any diversion from Britain on workers' rights or competition rules would scupper negotiations for a future trading relationship with the EU.

"There won't be a trade deal if there isn't a level playing field, one that is robust and credible", declared Mr Coveney.

"Standards will have to be maintained in regards to environmental standards, or workers' rights and so on.

"That is only half of the challenge, the other half is around fair competition. If the UK is trying to derive a competitive advantage for its own companies in order to trade into the EU - if that's the objective there will be no trade deal," he added.

Ian Blackford for the SNP claimed it was "fanciful to believe" Mr Johnson would complete a comprehensive trade arrangement with the EU by December and suggested there "could still be an extension to the transition".

The party leader said there was "real sadness" at the UK leaving the EU, noting how Scotland had benefited so much from EU membership, economically, socially and culturally.

He explained how a meeting in London with EU ambassadors on Wednesday had been "quite emotional".

He added: "We are demonstrating that message to keep a light on for us, that we fully intend to see Scotland become an independent country and to be a member of the EU. We see that very much as our destiny."

Elsewhere at Westminster, Tory Brexiteer backbencher Peter Bone suggested the Friday closest to the EU referendum date should be made a bank holiday, saying he planned to introduce a Bill calling for "United Kingdom Day" on the Friday closest to June 23 every year.

Meanwhile, the PM’s spokesman, answered one journalistic query about what the Government would be doing on Brexit come Saturday by saying: “Brexit will be done on Saturday. We won’t be speaking about it anymore.”