Tulip Siddiq has resigned as a shadow minister following Jeremy Corbyn’s decision to impose a three-line whip on Labour MPs to vote in favour of triggering Article 50.

In her resignation letter to the Labour leader Ms Siddiq, a shadow education minister, said: “I have always been clear – I do not represent Westminster in Hampstead and Kilburn, I represent Hampstead and Kilburn in Westminster. I feel that the most effective place for me to counter Theresa May’s hard Brexit is from the back benches.”

She added: “On the announcement of the three-line whip on the Article 50 vote, I therefore feel I have no choice but to resign from my frontbench role as shadow minister for early years. I do not support the triggering of Article 50 and cannot reconcile myself to the frontbench position”.

At the European Union referendum last year, around 75 per cent of her constituents voted to remain. She also has one of the most marginal seats in the country – at the 2015 election she won around 1,000 votes more than her closest rival.

“I will look carefully at amendments brought to the debate, consider them in their own right and work constructively to develop such guarantees,” she added. “I support Keir Starmer and my Labour colleagues, and know they are working to get the best deal for Britain throughout this process.”

Mr Corbyn confirmed the whip decision earlier on Thursday, telling Sky News: “It’s clearly a three-line whip. It is a vote on the article 50. We will put out a statement today to our members that we want them to vote for Article 50.”

According to news website Business Insider, Thangam Debbonaire, one of Labour’s whips said she will defy the whip if it is imposed.

But despite Ms Siddiq’s resignation reports that the shadow Business Secretary Clive Lewis would resign from his post proved to be inaccurate. He said on Thursday that he would vote for the Bill at the second reading, but stressed that Labour would seek to amend the legislation to stop Ms May using Brexit to “trash our rights”.

“I have been clear throughout that I respect the result of the referendum and will, therefore, join my colleagues in voting for the Bill on its second reading,” he said.

“However, Theresa May does not have a mandate to dictate the terms of Brexit without listening to the British people.

“The whole country should be involved in determining our shared future, which is why Labour has fought for the British people to have a say, through Parliament.

“Labour will seek to amend the Bill to prevent the Government using Brexit to trash our rights, public services, jobs and living standards while cutting taxes for the wealthiest.”

A source close to Cat Smith, the shadow voter engagement and youth affairs minister, told The Independent she has “no intention of resigning” from the Shadow Cabinet and will vote with the Labour whip to support the second reading of the EU Bill.

But Hampstead and Kilburn MP Tulip Siddiq has previously said she is ready to step down from her position as shadow education minister for early years if necessary in order to represent the views of her north London constituents, who voted overwhelmingly to remain.

On Sky News, the Labour leader added: “I fully understand the pressures and issues that members are under, those who represent Leave constituencies and those who represent Remain constituencies. Labour is in the almost unique position of having MPs representing constituencies in both directions and very strongly in both directions.

“I say to everyone, unite around the important issues of jobs, economy, security, rights, justice, those issues, and we will frame that relationship with Europe in the future, outside Europe but in concert with friends, whether those countries are in the EU or outside the EU.

“That’s the message we’re putting out. And I’m asking all of our MPs not to block Article 50 but to make sure it goes through.”

It is unclear, however, how strictly Mr Corbyn’s team will enforce the whip – with some sources speculating that there could be some flexibility. Historically, any minister or shadow minister who breaks a three-line whip is forced to leave their position on the front bench. “I wouldn’t assume anything about the consequences but usual expectations for a three-line whip apply,” said one senior Labour source.

The party has also tabled amendments to the Government’s 137 word Article 50 Bill, including a demand for a “meaningful” vote in Parliament on the final Brexit deal and key principles seeking to protect workers’ rights and securing “full tariff and impediment free access to the single market”.

Another amendment calls on Downing Street to guarantee the rights of EU nationals living in the UK, ensuring they are not bargaining chips in the forthcoming negotiations.

Keir Starmer, the shadow Brexit Secretary, added: “Now that Parliament has the right to trigger Article 50, we need to ensure there is proper grip and accountability built into the process.

Supreme Court Brexit Challenge Show all 13 1 /13 Supreme Court Brexit Challenge Supreme Court Brexit Challenge People wait to enter the public gallery outside the Supreme Court ahead of the challenge against a court ruling that Theresa May's government requires parliamentary approval to start the process of leaving the European Union, in Parliament Square, central London Reuters Supreme Court Brexit Challenge Gina Miller, co-founder of investment fund SCM Private arrives at the Supreme court in London on the first day of a four-day hearing Getty Supreme Court Brexit Challenge A man waves the EU flag in front of the Supreme Court Getty Supreme Court Brexit Challenge Satirical artist Kaya Mar poses with two of his paintings in front of the Supreme Court Getty Supreme Court Brexit Challenge Pro-Europe protestors dressed as Supreme Court Justices stand outside the Supreme Court ahead of the first day of a hearing into whether Parliament's consent is required before the Brexit process can begin. The eleven Supreme Court Justices will hear the government's appeal, following the High Court's recent decision that only Parliament can trigger Article 50 Getty Supreme Court Brexit Challenge The eleven Supreme Court Justices will hear the government's appeal, following the High Court's recent decision that only Parliament can trigger Article 50 Getty Supreme Court Brexit Challenge Businesswoman Gina Miller arrives at the Supreme Court ahead of the first day of a hearing into whether Parliament's consent is required before the Brexit process can begin Getty Supreme Court Brexit Challenge Attorney General Jeremy Wright arrives at the Supreme Court in London EPA Supreme Court Brexit Challenge Protesters outside the Supreme Court in London, where the Government is appealing against a ruling that the Prime Minister must seek MPs' approval to trigger the process of taking Britain out of the European Union PA wire Supreme Court Brexit Challenge A protesters wearing a judge's wigs and robes stands outside the Supreme Court ahead of the challenge against a court ruling that Theresa May's government requires parliamentary approval to start the process of leaving the European Union, in Parliament Square, central London Reuters Supreme Court Brexit Challenge A protester holds up a placard outside the Supreme Court ahead of the challenge against a court ruling that Theresa May's government requires parliamentary approval to start the process of leaving the European Union, in Parliament Square, central London Reuters Supreme Court Brexit Challenge Pro-Europe protestors dressed as Supreme Court Justices stand outside the Supreme Court Getty Supreme Court Brexit Challenge A man waiting to enter the public gallery waves a European Union flag outside the Supreme Court ahead of the challenge against a court ruling that Theresa May's government requires parliamentary approval to start the process of leaving the European Union, in Parliament Square, central London Reuters

“Labour’s amendments will also seek to ensure the Prime Minister secures the best deal for the whole country – including tariff and impediment free access to the single market and that there is no drop in workers’ rights.

“Labour’s amendments will significantly improve the Government’s Bill – in particular by ensuring the House of Commons has the first say on the final Brexit deal and that there are regular opportunities to hold the Government to account.