Mrs May will campaign in Scotland for the first time as polls put the Scottish Tories on course to win multiple seats at Westminster at the expense of the SNP.
The Prime Minister will join Ruth Davidson to stand against a second independence referendum and argue that the fortunes of Scotland and the UK are bound together.
“My message to the people of Scotland today is clear: if you vote for me it will strengthen my hand in the Brexit negotiations,” Mrs May is expected to say. “It will strengthen the Union, strengthen the economy and together the UK and Scotland will flourish. Because when Scotland is flourishing, the rest of the United Kingdom is flourishing too.”
Monday marks two decades since the 1997 Labour general election landslide in which all 11 Scottish Conservative MPs lost their seats.
The party has struggled in Scotland ever since, winning only one MP at every Westminster election and remaining stuck in third place in the Scottish Parliament until a resurgence last year, led by Ms Davidson.
The Prime Minister’s visit comes as a poll suggested the Conservatives could take as many as eight seats on 8 June. The YouGov poll for a national newspaper put the Conservatives on 28 per cent, an increase of 13 per cent on the 2015 general election.
Analysis suggests that would be enough to seize Moray from the SNP deputy leader Angus Robertson, and win in places like Aberdeenshire West and Kincardine, Aberdeen South and Dumfries and Galloway. Sources suggest the Prime Minister is set to make multiple campaign visits to Scotland to bolster the Conservative recovery.
Ms Davidson said the poll “reveals Theresa May is more in touch with people in Scotland than Nicola Sturgeon”.
She said: “Last month, Alex Salmond, Angus Robertson and Nicola Sturgeon all arrogantly declared that opposing a second referendum would stoke support for independence.
“In fact, most people in Scotland see the common sense in saying now is not the time for yet another divisive referendum campaign. The SNP should show some humility and take its unwanted plan for a referendum off the table immediately.”
SNP business manager Derek Mackay said the Tories’ strong polling showed “more than ever, it is only the SNP who can win against an out-of-control Tory Party under Theresa May.”
YouGov had good news for the other two unionist parties, with the Liberal Democrats on course to take East Dunbartonshire and Edinburgh West from the SNP to win seats, and Labour’s only Scottish MP holding on to his constituency despite his party’s poor overall standing.
The poll put support for Labour at 18 per cent in Scotland – ten percentage points lower than the Conservatives and well behind the SNP, who were on 41 per cent. It also showed 51 per cent of people were against a second independence referendum.
Kezia Dugdale dismissed reports that Labour is targeting just three seats in Scotland “absolute nonsense”.
Scottish Labour sources were quoted saying the party will focus its efforts on protecting Mr Murray’s Edinburgh South seat, and winning back East Renfrewshire and East Lothian.
Campaigning in Easterhouse in the east end of Glasgow, Ms Dugdale said: “We’re selecting candidates in all seats across the country. I’m immensely proud of the candidates we’ve selected, they represent a new generation of Labour candidates, many of them are standing for the first time.”
Jeremy Corbyn will hit back today at repeated attacks on his leadership qualities, claiming that a Conservative government will “hold Britain back” as people scale back their aspirations.
At a speech in east London today, the Labour leader will say a Conservative victory would deliver a “Brexit for the few” that will only benefit wealthy Tory backers who have a “get out of jail free card”.
Mr Corbyn will appeal for people to register to vote so their voice is heard in an election that “will define our times”.
He is expected to say: “Make no mistake, a Brexit for the few is now brewing. One where any money saved is handed out as tax cuts to the super-rich and their corporations. Where new trade deals with the US and elsewhere are used to drive down our working conditions, and environmental and food standards.”
Mr Corbyn will add: “Over 2.4 million young people are missing from the UK’s electoral register. Barely 40 per cent of 18 to 24-year olds turn out to vote.”