Labour was hit by a backbench revolt tonight when its attempt to force Theresa May to publish her Brexit plans sparked accusations it had fallen into a Tory trap.

A total of 23 Labour MPs defied their party leadership – and dozens more abstained – because the vote also meant supporting the Prime Minister’s timetable for triggering the Article 50 exit notice.

The clash came after the Government tagged on an amendment which meant MPs were also backing its policy to “invoke Article 50 by 31 March 2017”.

A string of Labour MPs rose to say this was a step too far – because No 10 has refused to say whether its “plan” will consist of any more than broadbrush aims.

But, with cross-party backing, the amendment passed with an overwhelming majority of 372, to the delight of many Tories who saw it as a big political moment.

For the first time – albeit on a non-binding vote – the Commons had backed the triggering of Article 50, a clear sign that few MPs are willing to obstruct the process, regardless of the legal battle in the Supreme Court.

On the Labour side, Angela Smith said she had “no confidence the Government will not try to wriggle out of the commitment to put a plan before this House”.

Ben Bradshaw said no answers had been promised on single market access, adding: “It in effect gives a blank cheque for us to invoke Article 50 by March without any of us being any the wiser about the Government’s intentions today.”

David Lammy told The Independent: “Will it answer specific points on single market membership? On free movement? On cooperation with our allies on security? On workers’ rights? Environmental protections?

“Will there be a list of so-called red lines? We don’t know.”

Jacob Rees-Mogg, a prominent Conservative Brexit supporter, taunted Labour by claiming the Government’s amendment had “cooked the Opposition’s goose”.

Earlier, Sir Keir Starmer, Labour’s Brexit spokesman, tried to calm backbench nerves by denying his party’s backing for the Government amendment had backfired.

He said that backing was conditional on the Prime Minister producing something better than a “late, vague plan” – or later challenges to the strategy would be made.

Insisting he “understands concerns” that the end of March is too early to trigger Article 50, Sir Keir added: “Labour does intend to shape the debate and head off a hard Brexit.”

The motion committed Ms May to “publishing the Government’s plan for leaving the EU before Article 50 is invoked”, but stopped short of demanding a full white or green paper.

Even Conservative MP Anna Soubry, a prominent Remain supporter, said she would back it, although she was “nervous and concerned”, adding: “I want a white paper, I want legislation.”

During the debate, Brexit Secretary David Davis promised to set out the Government’s “strategic plans” ahead of the triggering the withdrawal talks.

However, he also insisted it will not reveal anything which might “jeopardise our negotiating position”, suggesting MPs hoping for a detailed strategy will be disappointed.

Mr Davis also refused to give MPs a vote on what business leaders see as one of the most damaging potential Brexit decisions – to leave the EU’s customs union.

He said the Commons would be informed of the Government’s decision “when we are ready”, with several options still under consideration.

But a Government source said no vote would take place until the end of the two-year Article 50 process – and only if any new customs arrangements required legislation.

Earlier, Labour warned that leaving the union would bring “chaos and gridlock” for companies attempting to obtain supplies from EU countries.

Veteran Ken Clarke was the one Conservative to vote against the Article 50 timetable. He ridiculed Ms May’s latest soundbite, saying: “We’ll probably be told the plan is having a red, white and blue Brexit.”

Mr Davis also said it was “inconceivable” that MPs would not be given a vote on the eventual Brexit deal, probably in 2019.