The Mayor of London claims that Britain may not leave the European Union's (EU) Single Market.

On the eve of the Labour Party Conference, which is being held at Brighton this week, Sadiq Khan said in an exclusive interview with The Guardian that people "shouldn't speak too soon" about a "hard" Brexit, which would result in the UK leaving the EU's Single Market and Customs Union.

He condemned Prime Minister Theresa May for failing to achieve a mandate to pull Britain out of the EU in its entirety during this year's general election. He urged her to "re-position the goal posts" in the face of a humiliating result.

The Tories may not provide the British people with the sort of EU exit people voted for

The Mayor of London said that it is Labour's job to provide credible opposition to the Government's "hard" Brexit plans.

He said he does not understand what the Prime Minister means by the phrase "Brexit means Brexit" and hinted the Tories may not provide the British people with the sort of EU exit they voted for during last year's referendum.

Criticising the Conservatives' plans to curb EU immigration once the UK has left, he said he is glad that the one million European citizens living in London will remain here.

Labour will fight for the Tories' plans for a "hard" Brexit

Meanwhile, Shadow Brexit Secretary Keir Starmer said that Labour will fight the Tories' plans for a "hard" Brexit, calling for a general election before negotiations are complete.

He said he wants to replace his opposite number, David Davis, and negotiate an EU exit that protects workers' rights and Single Market access.

He said the "penny has finally dropped" for the Government after they had got stuck in the first phase of discussions, with the Brexit talks likely to end after March 2019.

Mr. Starmer said he wants his party to continue to fight for the kind of relationship with Europe that Labour has always believed in, adding that his colleagues have united on a single position of a transitional period before Britain fully leaves the trading bloc.

He said Labour will continue to campaign for retaining the benefits of Single Market membership.

Chuka Umuna called his party to support permanent Single Market membership

Speaking at the same conference event the Shadow Brexit Secretary made his remarks, Chuka Umuna called for his party to support permanent Single Market membership.

He thanked Mr. Starmer for attempting to provide clear red water between Labour and Eurosceptic Tories, adding he understands the former lawyer does not have an easy job pleasing all wings of the Labour Party.

Shadow Chancellor John McDonnell weighed into the Brexit debate unfolding in Labour, saying that his party could be in favour of a "changed Single Market" with reforms to the free movement of people. He said European leaders may agree to changes which retained some benefits of EU membership.

The Shadow Chancellor said he understood that the current rules regarding the free movement of people were unfair as they allowed employers to underpay workers'. Mr. McDonnell's comments come as Labour Leader Jeremy Corbyn prepares to open up a debate at his party's conference on arguments from Labour members about what his party's Brexit position should be.

The Corbyn ally told ITV's Peston on Sunday that he sympathises with the reasons why thousands of Labour voters chose to leave the EU last year, adding that if his party can persuade Brussels to amend existing rules on the Single Market and the free movement of people, voters may change their minds on leaving.

He is optimistic that Labour could push for transforming the Single Market in its entirety, adding that his party could change the current four freedoms of service, capital, goods and people in its entirety.

Shadow Home Secretary Diane Abbott told Sky News she welcomed Mrs May's plans for a transitional Brexit, commending her for ignoring pressure from "hard" Brexiteers in her own Cabinet and party. She said she was content with the Prime Minister's plans.