MPs are to probe the pensions regulator over its role in supervising thousands of pension plans that were this week left teetering on the edge of default following unprecedented market turmoil.

The work and pensions committee said on Sunday that it intended to write to The Pensions Regulator, which supervises about 5,200 corporate defined benefit plans that deliver a secure income to around 10mn members.

Thousands of pension plans that had used derivatives contracts to mitigate the impact of movements in bond prices on their liabilities faced emergency cash calls this week as gilt prices fell in an unprecedented sell-off triggered by chancellor Kwasi Kwarteng’s “mini” Budget.

The Bank of England stepped in and took emergency action to stabilise the financial markets with a £65bn bond-buying programme.

“I can confirm that the committee will be writing this week to TPR about issues raised by the Bank of England’s intervention,” said a spokesperson for the work and pensions committee.

The development comes as the liability hedging strategies at the heart of this week’s turmoil face mounting criticism.

Over the past two decades, pension funds have been encouraged by the regulator to adopt so-called liability-driven investment (LDI) strategies to help match their liabilities with their assets, often using derivatives.

These strategies require cash collateral to be held with an LDI manager; more cash may need to be added in response to market moves.

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