Plans for all private pension savings policy to be joined together in one place under a new Minister in the Treasury were rejected, Baroness Altmann has revealed.

The ex-Pensions Minister, who quit at the weekend, says she made proposals to David Cameron last year but was turned down. She said she put forward the idea again to Theresa May’s new Government before leaving her job.

Writing on her blog for the first time since she left Government, she explained: “Last week I suggested to Number 10 that I would be delighted to help the new Government with a radical overhaul of pensions policy responsibility.

“This could see all private pensions policy joined together in one place, under a Minister in the Treasury, while State Pension policy stays within the Department for Work and Pensions. Indeed, I proposed this to David Cameron last year after he asked me to be Pensions Minister but he decided against it.”

She said: “I think it makes sense for private pension savings policy to be run in one place, rather than being split across Departments. I would have been happy to do that in the new Government but only based in the Treasury, not the DWP.

“As the new state pension means an end to contracting out, the role of the DWP in private pensions is much reduced. Under the old system, millions of people were building a part of their state pension in a private pension scheme, paying lower National Insurance in exchange for giving up rights to part of their state pension.

“This policy has ended, so the state and private pensions are now totally separate. Therefore, it might be a good time to merge private pension policy together in one place rather than having contract-based private pensions policy resting in the Treasury, while trust-based pensions policy is made in DWP.”