Martin Lewis has issued a warning for millions of households that may be missing out on up to £400 in energy support.

There are only nine days left until the deadline for claiming Energy Bill Support Scheme vouchers before they become invalid. While direct debit customers received this discount automatically, prepayment meter customers had to redeem the discount via vouchers.

It comes after it was previously revealed that around £130 million of support is still available and remains unclaimed. Mr Lewis issued a warning on social media, reminding users that they still have time to claim the vouchers.

Join our WhatsApp Top Stories and Breaking News group by clicking this link

Writng on Twitter last night(June 22), he said: "IMPORTANT! You’ve 10 days left to redeem your energy voucher for non smart prepay meters." He also said on the Martin Lewis Money show last night: "If you're a prepayment energy customer, you only have 10 days left to claim those £66 or £67 month vouchers that you got...1.7 million are still unused, the deadline is the end of this month."

In order to get the support, customers need to visit a post office or PayPoint with their vouchers and ID before the deadline.

Adam Scorer, chief executive at National Energy Action, said: “We urge anyone who hasn’t yet claimed their vouchers to do so before the June 30 deadline and if you have friends and family that may not have used their vouchers, spread the word. It may be the support that keeps their lights on, their oven cooking, their hot showers running, through the summer.

"It’s vital money at a time when it’s never been needed more.”

Matthew Cole, head of Fuel Bank Foundation, the national charity that provides emergency fuel vouchers to prepayment meter customers, said: “We’re really concerned that hundreds of thousands of people with traditional prepayment meters are going to miss out on this vital financial support. As part of our own campaigning on this issue, we found that other reasons why vouchers haven’t been redeemed included not receiving them, due to incorrect details or the person having moved house and their records haven’t been updated, or they lost or deleted the voucher.

“However, whatever the reason, we want to reassure people that if they haven’t claimed their voucher, there is still time to do so.”