THERESA May will today begin the parliamentary fight of her life to secure her Brexit Plan as Nicola Sturgeon urged all MPs who opposed an extreme Brexit to “make a stand” against it.

The Prime Minister will give the opening statement on the first of five days of debate, telling MPs the 2016 referendum – the biggest democratic exercise in the country’s history - was a vote to end Britain’s EU membership and to “create a new role for our country in the world”.

She will argue delivering on that vote means creating a Brexit that takes back control of the UK’s borders, laws and money, claiming the agreed UK-EU deal does just that.

“A Brexit that sets ourselves on course for a better future outside the EU as a globally trading nation in charge of our own destiny and seizing the opportunities of trade with some of the fastest-growing and most dynamic economies across the world,” Mrs May will add.

But, underlining the parliamentary challenge facing the PM, Labour’s David Lammy branded her Brexit Plan a “cold betrayal of the British people” as it surrendered the country’s sovereignty after negotiations that resembled a “democratic fire sale”.

Speaking on behalf of the pro-EU Best for Britain campaign, the London MP added: “The deal being debated makes Britain poorer, less secure and without a veto over laws that will govern us for generations to come…To protect our democracy and restore sanity in politics, the public must be given the final say over Brexit."

For the second week running Mrs May met the First Minister in her rooms in the Commons. Ms Sturgeon stressed again how MPs should not face a false choice between her Brexit Plan and a no-deal outcome, which would threaten to be “utterly disastrous for jobs, business and living standards”.

Noting how the PM’s proposal was facing defeat next Tuesday, the FM stressed how a workable alternative was urgently needed.

“That means there should be an extension to the Article 50 process and we will join with those from other parties in trying to secure such an extension,” she declared.

Today in Luxembourg, an Advocate General of the European Court of Justice is due to publish his non-binding opinion on whether the UK can unilaterally revoke Article 50.

Ms Sturgeon, revealing that the SNP would put down its own amendment to the meaningful vote later this week, added: “With the UK Government’s own published figures now making clear that any kind of Brexit would make us all poorer, the time has come for all those who oppose the extreme Brexit championed by the right wing of the Tory Party to come together and make a stand.”

Following their meeting, a Downing St spokesman highlighted how the PM had spoken about the support she had received for her Brexit Plan from Scottish fishermen, farmers and business leaders like Sir Ian Wood, the Scottish oil tycoon, who on Monday backed it as a “workable proposal”.

Mrs May insisted the UK-EU deal gave business leaders the “clarity and certainty” they needed to protect jobs and living standards.

The spokesman added: “The PM urged the FM to listen to these voices in their support of the deal as opposed to risking a no-deal Brexit or going back to square one of the negotiations.”

On Monday, Mrs May saw “small groups” of Tory MPs in the Commons, an exercise set to be repeated throughout the week, in the hope of persuading colleagues of the merits of her Brexit Plan.

However, many Conservative backbenchers believe, as things stand, their leader will not get her deal through Parliament.

The key questions will be not only about the scale of the expected defeat in next Tuesday’s “meaningful vote” - that is due to lead to a Plan B being unveiled - but also on two other potential votes.

The first will be a no-confidence vote in the Conservative Government tabled within 24 hours by Labour. The expectation is Mrs May would win that vote.

More precarious is likely to be a no-confidence vote in her by Tory MPs; 48 signatures are needed.

Again, the scale of the opposition to the PM could be decisive even if she were to win it. In 1990 when Margaret Thatcher won most votes in the first leadership round, such was the scale of opposition that colleagues persuaded her she could not win in the second round and she resigned.

Asked if a similar exercise could take place, a loyal Government minister noted: “Then, we will know who the nutters are.”