THERESA May has hinted that she is preparing to ditch the Conservatives' flagship policy of maintaining a triple lock on Britain's state pensions.

The Prime Minister suggested she was looking to modify it, telling the BBC's Andrew Marr Show: "Under a Conservative government the state pension will still go up every year of the next parliament," but adding: "Exactly how we calculate that increase will be for the manifesto and, as I have just said, you will have to wait for the manifesto to see what's in it."

Labour has pledged to keep the triple lock in place for the country's 12.5 million pensioners; it ensures the state pension increases in line with wages, inflation or by 2.5 per cent; whichever is the highest.

John McDonnell, the Shadow Chancellor, said breaking the triple lock would mean some of the poorest pensioners would lost out. "I do not want to go backwards, I do not want pensioners going back into poverty again," he declared.

Meantime, Sir Steve Webb, a former pensions minister who is now director of policy at Royal London pensions company, suggested a "middle way" could be found to keep the triple lock, whereby costs were controlled and more generous annual increases were focused on older and poorer pensioners, who needed it most.

"The triple lock has delivered big improvements to pensioner incomes since 2010 but political parties will be concerned about the long-term cost implications of this policy on top of increased spending on health and social care associated with an ageing population," Sir Steve explained.

"On the other hand, abolishing the triple lock outright would leave many existing pensioners on relatively modest incomes with older pensioners facing much lower living standards than the newly retired.

"A middle way approach would preserve the triple lock for those who reached pension age under the old state pension system, whilst reverting to an earnings link for the newly retired. This would cap the cost of the triple lock whilst focusing spending increasingly on the older and poorer section of the pensioner population," he added.

A recent review by John Cridland, the former CBI Director General, who was appointed as the UK Government's independent reviewer of state pension age last year, recommended the triple lock be withdrawn in the next Parliament.

The political clash on the triple lock came as a survey suggested just one in seven people were approaching retirement without a private or workplace pension.

The Aegon Readiness Report said 1.21 million people were approaching retirement age with nothing to supplement their state pension while the figures were even more pronounced among women, 20 per cent of whom had no savings for retirement between the ages of 55 and 65 compared to 12 per cent of men.

The research found that the number of people without a private pension dropped dramatically as people entered the workplace. This, it said, showed the effect of auto-enrolment as many people benefited from employer pensions but the uptake then plateaued until retirement age.

Kate Smith, Head of Pensions at Aegon said: “Auto-enrolment which launched in 2012 as the Government’s flagship policy to increase the number of people saving for retirement, has undoubtedly been a success. To date 7.5 million employees have been enrolled into a workplace pension scheme and for many of these people, this will have been their first pension.

"However, as our figures show, there is a portion of the population who either feel unable to or are unwilling to save for retirement."

She added: “Our findings show how critical it is that the review of automatic enrolment brings more people into its scope and that we find equivalent nudges to help the self-employed and gig economy workers save for pensions as the default.”

In a separate development, the PM also revealed plans to stop "irresponsible bosses" bringing about a repeat of the BHS scandal, which saw retail tycoon Sir Philip Green branded the "unacceptable face of capitalism".

Her party's General Election manifesto will contain a commitment to give the Pensions Regulator new powers to scrutinise takeovers or "unsustainable" dividend payments that threaten the solvency of a company pension scheme. "In extreme cases," the regulator could be given new powers to block takeovers.