Business and energy secretary Greg Clark has been pressed to reveal the government’s plans for data-sharing arrangements for vulnerable customers.

The chair of the business, energy and industrial strategy (BEIS) select committee, Rachel Reeves, has written to Clark to demand an answer to whether the government will heed calls by Ofgem to remove legal barriers to the identification of vulnerable customers by suppliers.

“Ofgem and energy suppliers were very clear to us in evidence that a major obstacle to helping to protect vulnerable energy customers is the difficulty in identifying these customers due to insufficient data-sharing,” said Reeves.

“Ofgem has recommended a solution to this problem but the government has yet to act. When many low-income and vulnerable customers are missing out on current support such as the Warm Home Discount the government need to urgently spell out what it is doing to ensure vulnerable customers get the protection they deserve”.

In response to a Cabinet Office consultation on amendments to the 2017 Digital Economy Act, Ofgem recommended changes to data-sharing arrangements to enable customers on means-tested benefits to be protected by its safeguard tariffs without having to contact their supplier.

The price caps were introduced for all customers on prepayments meters in April and will be extended to a million customers receiving the Warm Home Discount (WHD) in February next year.

But without changes to data-sharing rules, Reeves said Ofgem will struggle to enact plans to extend the safeguard tariffs to a further two million vulnerable customers who do not receive the WHD by next winter.

The government is yet to publish its response to the consultation, which closed at the beginning of November. In her letter to Clark, Reeves asked for the BEIS committee be informed by the end of the month whether the government will follow Ofgem’s advice, and if so, when the changes will be introduced.

Reeves also questioned whether government alternatively intends to implement reforms to the WHD. She noted that multiple charities have argued for an end to the first come, first served rule for allocating support to the scheme’s broader group, saying they should instead be offered the discount on an unconditional basis.

She said the answers will be needed to inform the committee’s pre-legislative scrutiny of the government’s draft tariff cap bill next month (December).