Theresa May has warned her ministers not to think a General Election victory on 8 June is a done deal.
The Prime Minister used a Cabinet meeting to remind them that polls had been proved wrong "repeatedly" in the EU referendum, the 2015 election and the US presidential election.
Echoing comments made by Jeremy Corbyn himself, Mrs May pointed out the current Labour leader was considered a rank outsider to succeed Ed Miliband before pulling off a shock victory.
And party chairman Sir Patrick McLoughlin said the Conservatives would need to "campaign hard for every vote, in every part of the country".
Senior Tories have repeatedly talked up the prospects of Labour doing well, a move seen by many Westminster observers as a bid to avoid complacency among its supporters.
Conservative strategists fear that if their supporters believe victory is a foregone conclusion then they may not turn out to vote.
Mrs May told ministers it was important to get across the message that the country was being offered a choice between what she called "strong and stable leadership" under her or "a coalition of chaos and instability led by a floundering, weak and nonsensical Jeremy Corbyn that will put our nation's future at risk".
But in an indication of how high the Tories are setting their sights in this election, Mrs May parked her tanks directly on Labour's lawn by making a visit to South Wales.
It comes after a poll suggested the Conservatives could take a majority of votes cast in Wales for the first time in more than 150 years.
Mrs May warned again against complacency during the trip, telling a crowd in Bridgend that "every single vote will count".
The PM told them the poll was "the most important election this country has faced in my lifetime".
"An election in which every single vote will count. A really important election for the future of this country," she said.
"A vote for any other party would be a vote for a weak and failing Jeremy Corbyn propped up by a coalition of chaos which would risk our national future."