Theresa May will try to head off support for a second independence referendum as she meets Nicola Sturgeon later by suggesting the UK will secure a Brexit deal too good for Scotland to miss.

The Prime Minister will also meet officers from Police Scotland to discuss counter-terrorism in the wake of last Wednesday’s attack on Westminster.

Before meeting the First Minister she will tell staff at the UK’s Department for International Development (Dfid) base in East Kilbride that her vision for a "more united nation" includes a stronger devolution settlement.

She will also pledge to put the Union at the centre of all her government’s decisions.

She will say that her planned Brexit deal has at “its heart one over-arching goal: to build a more united nation.”

“In Scotland, Wales and Northern Ireland that means fully respecting, and indeed strengthening, the devolution settlements. But never allowing our Union to become looser and weaker, or our people to drift apart.

“So in those policy areas where the UK Government holds responsibility, I am determined that we will put the interests of the Union – both the parts and the whole – at the heart of our decision-making.”

The UK Government argues that Scotland stands to lose much more by separating itself from its largest market - the rest of the UK - than under Brexit.

Her visit comes just days before the two governments are expected to clash again over Brexit and independence.

Mrs May will officially file for divorce from the EU on Wednesday, kick-starting two years of exit negotiations.

But on the eve of that historic moment the Scottish Parliament is expected to back the First Minister's call for a second referendum.

The vote will plunge the two governments into conflict, after Mrs May declared that “now is not the time” for another vote.

The visit to Scotland is part of a ‘charm offensive’ of the devolved nations before Mrs May triggers Brexit talks.

She will also announce new temporary powers for Holyrood to amend some EU laws as they return to the UK.

The planned repatriation of powers has already provoked an almighty row between London and Edinburgh.

As part of the new Great Repeal Bill, Holyrood, along with Westminster and the other devolved administrations, will be given a "time-limited" ability to make legal changes to areas that affect devolved legislation.

Later this week UK Government is also expected to publish its response to Ms Sturgeon's "Scotland's Place in Europe" paper, and reject the First Minister's call for a separate deal for Scotland.

The Scottish Government accuse Mrs May of refusing to consider sensible ideas to preserve Scotland’s relationship with the EU.

As a result they say it is “essential” that the Scottish people is given a say in a referendum.

Meanwhile, a new poll shows rising numbers of households across the UK fear Mrs May’s planned ‘Hard’ Brexit will result in a further decade of economic gloom.

People living in Scotland are the most pessimistic about the UK economy’s long-term prospects.

The poll found that 29 per cent of British households think Brexit will have a positive long-term effect on the economy, down from 39 per cent last July.

More than half, 53 per cent, believe it will have a negative effect, up from 42 per cent last summer.

Ipsos MOR surveyed 1,500 people across the UK

Elsewhere, a Conservative minister has defended controversial "Henry VIII"-style powers to change European Union laws when they return to the UK without the full scrutiny of MPs.

Commons Leader David Lidington insisted that the plans, to make changes to repatriated EU laws without full debates and votes by MPs, were necessary to make "technical" changes quickly.

But Labour leader Jeremy Corbyn has vowed to oppose the "essentially dictatorial powers".

There were also claims ministers could allow EU migrants to continue to receive child benefit for youngsters outside the UK after Brexit.

The Sunday Times reported that a paper by the Department for Exiting the European Union recommends that all those in the country before Wednesday should keep the benefit.

Ministers have been warned that any attempt to withdraw the payments risks tit-for-tat retaliation from Brussels.

The payment of benefits for children who do not live in the UK has been hugely controversial.

The Conservative manifesto at the last general election pledged to limit tax credits and child benefits to only EU migrants who have been in the UK for four years.