Theresa May will claim German Chancellor Angela Merkel's tough stance on Brexit shows the need for a Tory election win to give the UK the "strongest possible hand" in the forthcoming negotiations.
The Prime Minister will use a campaign visit to Leeds to urge Labour supporters to lend her their vote rather than put Jeremy Corbyn into Number 10.
She will say that every vote for the Tories will improve her position when facing European leaders in the "tough" talks ahead.
Leeds voted narrowly for Remain in the European Union referendum, but the Yorkshire and the Humber region as a whole backed Brexit.
German leader Mrs Merkel used a speech in the Bundestag to claimed the UK has "illusions" about the realities of Brexit, insisting there was no way it could continue to enjoy the same rights it had as a member of the EU.
She also insisted that the divorce from Brussels, including a bill of up to £50 billion, would need to be agreed before talks on the future relationship between the UK and EU could commence.
Mrs May will say: "We have seen Chancellor Merkel's comments today. She says the UK has 'illusions' about the process and that the 27 member states of the European Union agree.
"We can see how tough those negotiations are going to be at times.
"Yet our opponents are already seeking to disrupt those negotiations, at the same time as 27 other European countries line up to oppose us.
"That approach can only mean one thing, uncertainty and instability, bringing grave risk to our growing economy with higher taxes, fewer jobs, more waste and more debt.
"So we need the strongest possible hand, the strongest possible mandate and the strongest possible leadership as we go into those talks."
Mrs May will seek to exploit divisions within Labour over its leadership by telling voters: "I know this city is one of the places that people call a 'traditional Labour area'.
"But here, and in every constituency across the country, it may say Labour on the ballot, but it's Jeremy Corbyn that gets the vote."
She will again use her key campaign message that the election is a choice between "strong and stable leadership" from her or a "coalition of chaos" under Mr Corbyn.
She will add: "That is why in this election, the most important election this country has faced in my lifetime, every single vote counts.
"And everyone in our country has a positive reason to lend me their vote.
"Because this election is not about who you may have voted for in the past. It is about voting in the national interest. Voting for the future.
"And every vote cast for me through my local Conservative candidates in cities like Leeds, and in towns and cities across the UK, will strengthen my hand when I negotiate with the prime ministers, presidents and chancellors of Europe in the months ahead."
Labour's national elections chairman Andrew Gwynne said: "Theresa May is going to extraordinary lengths to blinker the British public and make this election about anything other than her record in government.
"The people of Leeds won't be fooled: the only party of working people is the Labour Party.
"Under the Tories, working people have picked up the bill while those at the top have received tens of billions of pounds of tax breaks. Wages have stagnated, public services have suffered huge cuts and our NHS is in crisis.
"It is clearer than ever that the Tories are for the few, not the many. Rather than uniting the country and tackling the challenges we face, their policies are divisive and are taking us backwards."