Jackson Carlaw has faced criticism for speculating on the impact the coronavirus pandemic will have on next year's Holyrood election.
The Scottish Conservatives leader said it would now "look ridiculous" if the SNP pushes for independence at next year's poll.
Mr Carlaw added a factor in Scotland's response to coronavirus was the "economic resilience" of the UK.
But the SNP claimed the remarks were inappropriate.
A party spokesman said "the last thing any Scottish politician on any side of the constitutional debate should be doing is trying to use the appalling crisis we all currently face as an argument for or against independence".
In an interview with the PA news agency, Mr Carlaw said there will be no guarantee that the SNP will retain its place as the largest party in Holyrood at next year's election.
He said: "I still maintain that by the time we come to the election next year, the Scottish Government will have been in power for 14 years, people will have come through an exhausting crisis.
"Let's remember, (Winston) Churchill won the war but the people turned to (Clement) Attlee after it."
Mr Carlaw said he believes making Scotland's constitutional future a centrepiece of its 2021 campaign may hurt the SNP.
He said: "I don't expect nationalists to surrender the ground at this point, but quite honestly I think it will look ridiculous if the first debate that the nationalist movement want to have when we get to the other side of this is 'let's go gung ho for independence next year' then more fool them if they do.
"I think the public will look at that and say 'are you kidding?'"
Mr Carlaw went further, claiming one of the major factors in Scotland being able to tackle the outbreak was the "economic resilience and strength" of the whole of the UK.
A spokesman for the SNP said: "Jackson Carlaw may be thinking about next year's election - but the first minister and the SNP government are fully focused on tackling the current health crisis and the impact on jobs and incomes.
"Mr Carlaw needs to be very careful with his arguments - the coronavirus pandemic is not a Scottish, British or European issue, it is a global one."