Watford MP Richard Harrington has been appointed as a replacement for pensions minister Ros Altmann.
His official title is parliamentary under secretary of state at the Department for Work and Pensions.
However, a DWP spokesman confirms he will be known as the pensions minister. It is not yet clear whether his brief will differ from Altmann’s.
An MP since 2010, Harrington was a member of the international development committee, general secretary of the all party Kashmir group and vice chairman of the all party film group.
Last week, Portsmouth North MP Penny Mordaunt was appointed minister of state for the DWP. It is believed she will be responsible for disability policy.
Altmann left her post at the weekend, however it is unclear whether she was sacked or resigned.
In a letter to the Prime Minister she said: “I am at heart a policy expert, rather than a politician.”
She also set out a series of priorities for her successor to tackle as the UK enters “uncharted waters”.
These include an overhaul of pensions tax relief, though not a move to the TEE model, a major review of the defined benefit system, and “fair treatment for women” affected by changes to the state pension age.