THERESA May laid out Brexit plans that will keep Britain in the European Union in all but name until 2021, provoking claims of “betrayal” by leading Leave campaigners.

In a landmark speech in Florence, the Prime Minister announced that the UK would pay at least £17 million into EU budgets after Brexit, abide by European court rulings and continue with the free movement of European workers until the end of a two-year transition period.

Ms May also signalled that Britain would pay its debts to the bloc and said for the first time that the government would “honour commitments” made during its membership.

Herald View: Choppy waters still lie in wait for good ship Brexit

Her address in the Tuscan capital was aimed at ending the deadlock in Brexit negotiations and creating a positive background for official talks which are due to resume next week in Brussels.

But while Mrs May’s ‘olive branch’ of concessions was welcomed by some who are closely involved in the process, other observers expressed concern over the lack of fine detail and the prospect of two further years before British ties with the EU are severed completely.

EU chief Brexit negotiator Michel Barnier said that while the Prime Minister had “expressed a constructive spirit” and shown a willingness to move forward, he warned that questions remain over key elements including Mrs May’s financial offer and that more work was needed before talks could progress to a future free trade deal.

Herald View: Choppy waters still lie in wait for good ship Brexit

The much anticipated address was hailed as “positive, optimistic and dynamic” by Foreign Secretary Boris Johnson, who looked set to resign earlier this week over perceived differences with the Prime Minister over Brexit.

But it sparked a barrage of criticism from leading Leave campaigner, Nigel Farage, the former Ukip leader, who accused Mrs May of betraying Brexit voters.

Describing her speech as “a tragic waste of a golden opportunity”, Mr Farage said: “Britain will have had to wait five years since the Brexit vote before actually getting out of the EU and settling its future.

“We will continue to be subject to the EU’s crazy freedom of movement policy; our huge net payments of up to £10bn per year to the EU will go on; and all EU laws and regulations will remain in place and will be judged by the European Court of Justice in Luxembourg.

“This is not what the majority voted for and it represents a victory of the EU Establishment over Britain’s 17.4 million Leave voters. It is nothing short of a democratic abomination,” he added.

Herald View: Choppy waters still lie in wait for good ship Brexit

The pound fell to a daily low against both the US dollar and euro as investors reacted to Mrs May’s vision of Britain’s future with the EU in an in a speech to a gathering of businessmen and journalists at the Santa Maria Novella church, in Florence.

Warning that more time was needed to work on Brexit details, the Tory leader stressed “We have to get this right”, before offering a string of proposals designed to pave the way for an amicable divorce.

At the centre of her vision is the two year transition period after Britain formally leaves the EU in March 2019 when Britain is due to formally leave the EU. She said over the 24 month period after March 2019, trade would continue on current terms, and EU migrants will still be able to live and work in the UK, although they will have to register with authorities.

Mrs May also hinted that the UK could offer significantly more than the £18bn bill to cover its annual contributions over two years. “I do not want our partners to fear that they will need to pay more or receive less over the remainder of the current budget plan as a result of our decision to leave. The UK will honour commitments we have made during the period of our membership,” she said.

The Prime Minister also promised:

• A “bold new security” arrangement, and offered a treaty on maintain law enforcement and criminal justice cooperating. She added that the UK was “unconditionally committed to maintaining Europe’s security.

• To protect EU citizens' rights in the Brexit treaty, and allow British courts to take the rulings of the European Court of Justice into account when judging disputed cases

• Ruled out an economic partnership based on existing agreements with Canada or Norway, and suggested instead a “creative solution.” to reflect the UK’s current relationship with the EU.

With no clarification surrounding questions over how the Irish border may operate,e under Brexit, other than a reiteration that the UK will not accept “physical infrastructure at the border” between Northern Ireland and the Republic of Ireland. Sinn Fein president Gerry Adams, said: “It was nothing but the same old story.”

Mrs May’s speech received cautious reviews in the continental press, which typically portrays her as floundering over Brexit.

Germany’s Suddeutsche Zeitung called her offer of a transition “brave” but its commentator Stefan Kornelius said she was in a “pitiful position”, like a bug stuck on its back and waving its legs desperately.

There was mocking in Italy too. “Theresa May retreats from Dunkirk with no enemy at her back,” read a headline in the Italian edition of the Huffington Post.

Foreign affairs expert Roberto Somella said all that remained of Mrs May’s aspirations were “beautiful words about an innocent illusion, to get out of a European ‘cage’ which for many had become a refuge.”

At home, Labour Leader Jeremy Corbyn said the speech suggested the PM had “listened to Labour and faced up to the reality that Britain needs a transition on the same basic terms to provide stability for businesses and workers”.

He added: “Our whole point throughout this whole process has been a Brexit that damages employment and jobs is very, very dangerous for everybody in this country.”

However Manfred Weber, a German MEP and close ally of Chancellor Angela Merkel, said: “ In substance, PM May is bringing no more clarity to London’s positions. I am even more concerned now.”