Sterling rallied on Wednesday morning as British Prime Minister Theresa May conceded to a "full and transparent" House of Commons debate on Brexit.

Tuesday had brought fresh lows for the currency, following comments from May’s spokeswoman that British MPs wouldn’t get a vote on whether to trigger article 50.

Volatile trading overnight saw one euro quoted at 91p – it has eased back to just below 90p today.

The pound's rebound to just under $1.23 comes as the British government tables a surprise amendment to prevent rebellious Conservative MPs voting with the opposition, for extra parliamentary scrutiny on the Brexit process.

In a move described by opposition sources as a "huge climbdown", the government tried to persuade several Tory MPs to refuse to back Labour's Opposition Day motion, which called for the parliament to be able to scrutinise a plan before Article 50 is triggered.

A number of Tories – including some backers of the Leave campaign – are deeply concerned about Theresa May's announcement that Article 50 will be triggered by the end of March and, in particular, the clear signal that Britain is leaving the single market.

Since the Conservative Party Conference, the pound has fallen by 6%, and some financial firms have accelerated plans to pull jobs out of London.

On Tuesday evening, May offered an amendment to accept extra scrutiny as long as it "does not undermine the negotiating position of the government".

It also increases the chances of some sort of Green paper or negotiating strategy having to be presented to the House of Commons.

A Number 10 source said: "The government is focused on delivering on Brexit. We have always been clear that Parliament has an important role to play, and this motion reflects that."

Neil Carmichael, a Tory MP and chair of the Conservative Group for Europe, called it "a step in the right direction".

A number of Conservative MPs are expected to criticise the lack of scrutiny on the government's Brexit approach.
Labour also challenged the government to answer 170 questions on the detail of its Brexit plan – one for every day before the end-of-March deadline for triggering Article 50.

The UK's shadow foreign secretary Emily Thornberry and shadow Brexit secretary Sir Keir Starmer said a failure to respond would reinforce the impression that ministers were "blundering" into negotiations with the EU with a "flawed plan A" and "no plan B whatsoever".

This week, a court case begins which seeks to force the British government to hold a vote in parliament before triggering Article 50.