Kemi Badenoch has committed to keeping the pension triple lock indefinitely – opening up an election divide with Labour.

The Tory leader has ended speculation she could follow Andy Burnham in ditching the mechanism which has helped protect the value of the basic state pension for years.

Asked if the Conservatives would keep the policy ‘in perpetuity’, she told the BBC: ‘That is what we have promised. There is nothing that has happened that has made me change my mind.’

The intervention came as new analysis suggested Andy Burnham’s pledge to ditch the current triple lock mechanism could cost some workers up to £38,000 in retirement.

The Prime Minister revealed last week that Labour will scrap the existing system in 2030. Legislation to ditch the triple lock could come as soon as next year, despite Labour’s manifesto commitment to keep the triple lock.

Mr Burnham said the move could help pay for his plan to create an NHS-style National Care Service for social care. Official estimates suggest it could save £15 billion a year by 2040 – money that would otherwise have gone to pensioners.

But Mrs Badenoch said the PM had yet to show how modest savings in the early years of the next decade could fund a new social care system he has said he wants to get underway in 2030.

In a series of interviews to mark the start of the Conservative Party conference in Birmingham, Mrs Badenoch also delivered a fresh hint she is drawing up plans to abolish inheritance tax, describing the hated levy as ‘morally wrong’.

She also unveiled new plans to scrap the £100,000 earnings threshold for qualifying for free childcare. Currently, any family with one member earning more than that loses all entitlement to free childcare, leaving some workers thousands of pounds worse off if they accept a promotion or pay rise.

Some senior Tories, including former chancellor Sir Jeremy Hunt and shadow communities secretary Katie Lam, have questioned the long term sustainability of the triple lock.

But Mrs Badenoch said the focus for welfare reform should be getting more people into work.

‘What is going wrong in our economy is not lots of elderly people earning £10,000, £12,000 a year on the state pension, it is the huge number of people who can work who don’t work,’ she said.

‘Going after the triple lock is simply moving money around. I am talking about growing the economy, getting people into work, making us more productive, bringing back the link between savings and growth. What we’re doing with this argument about the triple lock is a ledger on the budget line, there are more fundamental problems that need to be tackled.

‘The fact is, the triple lock and pensions are things that people have contributed to. Conservatives believe that if you have contributed then you deserve to get your state pension. What we don’t want to see is people going after the elderly, chasing after vulnerable and disabled people and then be an extremely large cohort of people who can work who are not working are left alone.’

Her intervention creates a clear dividing line with Labour ahead of an election which many senior Tories believe could come as soon as next year.

It came as analysis by the Sunday Times revealed that younger workers will be the worst hit by Labour’s move away from the existing triple lock.

The report suggested that Generation X workers born between 1965 and 1980 would be worse off than they would have been by an average of £16,800 to £23,170 over the course of a 20-year retirement.

Millennials born between 1981 and 1996 would suffer an average hit of £28,140, while those in Generation Z, born between 1997 and 2012 would be worse off by £38,400.

Under the terms of the triple lock, which was introduced in 2011, the state pension rises by whichever is the highest of inflation, earnings or 2.5 per cent.

In the new plan, the direct uprating with earnings will be lost, leaving the pension rising by either inflation or 2.5 per cent. Ministers have said a separate mechanism will ensure the pension does not fall below 30 per cent of average earnings over time.

The change means that the state pension will increase more slowly over time, leaving younger workers hit hardest.

Ministers insist older people will see the value of their pensions protected by the 'adjusted' triple lock, as well as benefiting from free personal care if they need social care in later life.