Pro-EU MPs insist Theresa May has not been given the green light to pursue a hard Brexit, despite last night’s overwhelming Commons backing for her timetable.

Labour is facing a backlash after it supported the prime minister’s policy to “invoke Article 50 by 31 March 2017” in return for a vague commitment that she must publish a “plan” before then.

A total of 23 Labour MPs defied their party leadership – and dozens more abstained – but the motion passed with a huge majority of 372, to the delight of Brexit supporters.

The vote is widely seen as a clear sign that few MPs will obstruct the process, regardless of the legal battle in the Supreme Court over whether they must give their consent.

Today, one of those rebels – former minister Ben Bradshaw – did not criticise Labour’s tactics, saying Brexit spokesman Keir Starmer was doing “a brilliant job”.

But he insisted the Commons fight was far from over, predicting future votes on membership of the single market, of the customs union and on the rights of EU citizens.

On the Conservative side, former Attorney General Dominic Grieve said MPs would continue to push back against the “appalling damage” that could be inflicted by a botched Brexit.

Mr Bradshaw told Radio 4’s Today programme: “I was not prepared, yesterday, to commit myself to what I believe to be a rushed, ill-thought through and unnecessarily tight timetable, given the German and French elections.”

On the promised “plan”, he said: “I suspect that, when they come up with not very much, more people – including quite a number of Conservatives – may be prepared to vote differently.”

There was a “huge cross-party majority” to retain, at the very least, tariff-free access to the single market, he said, adding: “That’s what we need to explore in this process.”

Mr Grieve voted for the motion, believing a significant concession had been extracted by Labour in the form of the plan that must now be produced.

He agreed with the suggestion that last night’s vote was merely a “grand opinion poll of MPs” – when it was legal changes that mattered.

Mr Grieve said: “We have an absolute entitlement - indeed a duty, as members of parliament – to try to safeguard the interests and well-being of our constituents.

“We do not govern in this country by referendum or, for that matter, by parliamentary motions in the House of Commons.”

But the euphoria of pro-Brexit MPs was summed up by Iain Duncan Smith, who said the Commons had given Ms May a “blank cheque” to “get on with it” and trigger Article 50 by the end of March.

The 23 Labour MPs who voted against the Government amendment to give backing to the March timetable included three shadow ministers - Tulip Siddiq, Catherine West and Daniel Zeichner.

The Labour party has not said whether any action will be taken against them for defying the whip, which has traditionally been viewed as a sackable offence.