THERESA May has signalled that if the Conservative Party wins the General Election it will set its face against facilitating a second Scottish independence referendum for the entirety of the next Westminster Parliament, that is, until 2022.

At her party's manifesto launch in the Labour marginal of Halifax, the Prime Minister made a pitch for the centre ground to woo traditional Labour supporters to her cause, declaring: "My mainstream government will deliver for mainstream Britain."

She ditched David Cameron's pledge not to raise income tax or national insurance, abandoned the triple lock guarantee that state pensions would rise by at least 2.5 per cent a year, and said the nation's books would be balanced by 2025, some three years later than promised in the last parliament.

With the Brexit process due to begin in earnest once the election is over, Mrs May said Britain was facing the most challenging period in the past 60 years.

"It is why in this election, more than ever before, it is time to put the old, tribal politics behind us and to come together in the national interest; united in our desire to make success of Brexit."

Mrs May defended her proposal to means-test the winter fuel payment so it is only paid to the less well-off pensioners as a move to create fairness "across the generations" but the controversial proposal will not be replicated in Scotland when the Scottish Tories unveil their manifesto in Edinburgh on Friday; it was stressed how Scotland had a "different backdrop" to the one in England regarding climate, geography and more people being off-grid.

Speculation was mounting that the PM could attend the Scottish party's launch.

Under a section headed "Our precious Union," the UK party's programme for power says: "The United Kingdom has voted to leave the European Union but some would disrupt our attempts to get the best deal for Scotland and the United Kingdom with calls for a divisive referendum that the people of Scotland do not want.

"We have been very clear that now is not the time for another referendum on independence. In order for a referendum to be fair, legal and decisive, it cannot take place until the Brexit process has played out and it should not take place unless there is public consent for it to happen. This is a time to pull together, not apart."

David Mundell, the Scottish Secretary, when asked at the manifesto launch what was meant by "until the Brexit process has played out," said: "I don't think anyone has a crystal ball as to how long the Brexit process will take but it's quite clear it is not just the negotiations, it's the transition; there's an acknowledgement there's going to be a significant transition period and an implementation period."

The talks period is due to end in March 2019 but Anna Soubry, the former Business Minister, and a leading Remainer in the EU referendum campaign, has stressed how a transitional period could “go on for years”.

Mr Mundell suggested one key issue about how lengthy the process might be was the repatriation of "significant powers" to Holyrood from the EU.

"The Nationalists claim some power-grab but how can people decide until they see what has exactly happened? Until all of that has happened, I don' think it is fair to suggest that you could have an independence referendum because people can't make an informed judgement."

He added: "There are many of the Nationalists who voted to leave, the 500,000, who tell me on the doorstep that they want to see the Brexit process complete, they want to see Brexit bedded in before there is any talk of another referendum."

The manifesto, which one Tory source pointed out had the words "Conservative and Unionist Party" printed on each of its 84 pages, notes how the Scottish economy has "lagged behind the rest of the UK" in recent years and promises to take concerted action to help secure the long-term sustainability of the Scottish economy.

"Scotland and Scottish industries will be central to our industrial strategy," it insists.

The Tories' prospectus for power also pledges to:

*establish a Borderlands Growth Deal, involving all councils on either side of the border "to help secure prosperity in southern Scotland";

*start to move out of London the "shared institutions of the Union" such as Channel Four;

*set up a "United Kingdom Shared Prosperity Fund" to share out EU structural funds that come back to the UK following Brexit to "reduce inequalities between communities across our four nations" and

*protect the interests of Scottish farmers and fishermen and would use the "United Kingdom's muscle" to promote Scottish exports around the world.

Jeremy Corbyn, the Labour leader, said millions of pensioners were being betrayed by the Tories' manifesto.

"She is hitting older people with a classic Nasty Party triple whammy: scrapping the triple lock on pensions, removing the Winter Fuel Allowance and forcing those who need social care to pay for it with their homes," he said.

Angus Robertson, the SNP deputy leader, said: "The Tory manifesto is a cruel and callous attack on families with deep austerity cuts that will hit pensioners, families, and our public services.

"Theresa May talked about 'hard choices' and these will affect pensioners, disabled people, the vulnerable, and those on middle and low incomes."