LONDON – Prime Minister Theresa May will tell Scots that Britain will be an “unstoppable force” if Scotland stays part of the union with the United Kingdom.

According to excerpts from her speech, which May will deliver to staff at the Department for International Development in East Kilbride in Scotland later on Monday, the prime minister will say that the “the strength and stability” of the over 300-year union between Scotland, England, Wales and Northern Ireland – which together make up the UK – will “become even more important” when Britain leaves the European Union.

“When this great union of nations – England, Scotland, Wales and Northern Ireland – sets its mind on something and works together with determination, we are an unstoppable force,” May will say.

“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. A more united nation means working actively to bring people and communities together by promoting policies which support integration and social cohesion.

“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.”

When this great union of nations... sets its mind on something and works together with determination, we are an unstoppable force

On March 16, May announced her intention to block a second Scottish independence referendum before Britain has left the EU. Scottish First Minister Nicola Sturgeon had said that she intends to call a referendum at some point between Autumn 2018 and Spring 2019.

However, May said "now is not the time" to hold a referendum as it would "not be fair" to expect the Scottish people to vote again when the UK's future relationship with EU is still unclear.

"Just at this point, all our energies should be focused on our negotiations with the European Union about our future relationship," May said at the time.

"To be talking about an independence referendum will make it more difficult for us to be able to get the right deal for Scotland, and the right deal for the UK. And more than that, I think it wouldn't be fair to the people of Scotland because they're being asked to make a crucial decision without all the necessary information - without knowing what the future partnership would be, or what the alternative of an independent Scotland would look like."

On March 22, members of Scottish parliament were expected to back a motion calling for a new independence vote at some point between Autumn 2018 and Spring 2019. However, the Scottish Parliament suspended a vote on whether to hold a second referendum on independence from the UK, following the terror attack in Westminster.

The motion states that it is "the sovereign right" of the Scottish people to decide their future and calls for the UK government to hand over the necessary powers for a new poll.

The ruling Scottish National Party holds just 48% of seats in the parliament with the opposition Labour, Conservative and Liberal Democrat parties all opposed to a new poll. However, support from the Scottish Green party was set to allow the motion to pass.

Meanwhile, May is set to trigger Article 50 on Wednesday and thereby start the formal two-year Brexit negotiation process.

May will say:

"The work you do here - in conjunction with your colleagues at the Department for International Development in London - says something important about Britain.

"It says that we are a kind and generous country. It says that we are a big country that will never let down - or turn our back on - those in need. And it says that we are a country that does - and will always - meet our commitments to the world - and particularly to those who so desperately need our support.

"And that is important to remember.

"For we stand on the threshold of a significant moment for Britain as we begin the negotiations that will lead us towards a new partnership with Europe.

"And I want to make it absolutely clear as we move through this process that this is not - in any sense - the moment that Britain steps back from the world. Indeed, we are going to take this opportunity to forge a more Global Britain. The closest friend and ally with Europe, but also a country that looks beyond Europe to build relationships with old friends and new allies alike."