Tory leadership hopefuls should stop coming out with "populist nonsense" about tax cuts, Ken Clarke has said.
The former chancellor said he would love to see taxes coming down but that the economy was clearly not able to support them now.
It comes after would-be replacements for Boris Johnson unveiled pledge after pledge designed to woo Tory members.
Nadhim Zahawi, who took over as chancellor last week, on Monday said he would make £50 billion a year in tax cuts – as much as the entire budgets of the Ministry of Defence and Foreign Office.
Sajid Javid also said he would make £40 billion in tax cuts including taking 10p off the price of petrol, cutting income tax, and scrapping the recent rise in national insurance.
Speaking on Monday night on the BBC's Newsnight programme Mr Clarke said:
"I would like to see tax cuts, of course I would, from the present extraordinary levels. But when the economy has been put into a state where you could responsibly afford them.
"Tough and difficult decisions are require right now, not more populist nonsense on top of what we've sometimes had already."
Other candidates like Penny Mordaunt and Tom Tugendhat have both said that tax cuts are important but that other economic reform measures are needed to stimulate growth.
Mr Zahawi insisted on Tuesday that cutting taxes “isn’t a fairytale” in a swipe at his leadership rival Rishi Sunak, as he set out his pitch to the Conservative membership.
Mr Sunak said leadership required "honesty and responsibility, not fairytales" and said he would only cut taxes after getting inflation under control.
In March Mr Clarke, who served as chancellor from 1993 to 1997, branded Mr Sunak himself "reckless" for pledging to cut income tax three years in advance.
In office the former chancellor himself prioritised low taxes and balanced budgets, cutting the basic rate of income tax from 25 per cent to 23 per cent, and also cut UK Government spending as a percentage of GDP and the budget deficit.
It was announced on Monday that the new leader of the Conservative party, to replace Boris Johnson ,would be announced on 5 September, after a hot summer of campaigning.
