This is why Martin Lewis is campaigning to free 170,000 mortgage prisoners

Mr Lewis, who founded the consumer website MoneySavingExpert.com (MSE), is supporting a study which aims to highlight the economic cost of failing to provide redress for Britain's mortgage prisoners.

Mortgage prisoners are consumers who are unfairly trapped in their current deal, often with an inactive or unregulated lender.

They are sometimes paying far higher rates than they need to. This group is rejected for all remortgages - cheaper mortgage deals elsewhere- because they don’t meet strict borrowing criteria brought in after the financial crash, even though they are keeping up with repayments.

Many mortgage prisoners have also told MSE that they face an "extreme emotional and physical burden".

MSE’s campaigns team has instructed the London School of Economics and Political Science (LSE) to carry out new research which will look for solutions that could "unchain" mortgage prisoners.

This research has been funded by a five-figure donation from Mr Lewis, through his charitable fund.

The aim is to find evidence-based policy solutions, which will push the Government to step in and rescue mortgage prisoners.

Mr Lewis said: “The cost of mortgage prisoners doesn’t just fall on the individuals, it falls across society.

"The impact of leaving people locked in to unaffordable mortgages can be catastrophic. It can leave them dependent on the state, with little savings for old age, and even adding to NHS costs with the hideous and disastrous mental health impact that can occur when you destroy someone’s financial life choices.

“So over the next few months, we’re asking the LSE to explore a range of cost-effective, practical policy solutions the Government could employ to rescue mortgage prisoners – which we can then take to the Treasury.

"I won’t pre-empt their work, but it’ll include a feasibility study of solutions – for example, subsidising competitive lenders to enable them to offer mortgage prisoners a decent deal. Then I hope where possible that can be compared to the cost to the economy of doing nothing – and leaving mortgage prisoners locked in for life or losing their homes.

Mr Lewis added: “It’s worth remembering that the Government spent billions bailing out one set of victims of the financial crash – the banks.

"Yet it’s done nothing to help another set – those locked into high-rate mortgages. In fact it’s actually responsible for some of their pain, selling the mortgage customers of former lenders like Northern Rock and Bradford & Bingley to unregulated, inactive lenders who have no other mortgage products, leaving these mortgage prisoners with no option other than to try to afford to keep paying obscene rates.”

Earlier this week, campaigners called on the Government to implement a "no consent, no sale" bill which would make it illegal to sell mortgages to inactive and unregulated lenders.

Rachel Neale, the UK Mortgage Prisoners’ lead campaigner, said that nobody’s home should be sold to a so-called "vulture" fund.

The City Minister John Glen has called on UK lenders to take swift action to ensure Britain’s mortgage prisoners gain access to better deals.

An HM Treasury spokesperson said: "We know that being unable to switch your mortgage can be stressful.

"That’s why we’ve introduced rules that make it easier for some customers to switch.

"We now want to see more people offered these new deals and have been working closely with banks on this important matter."

The Economic Secretary wrote to UK Finance last week to urge the industry to do more to help those eligible to switch to a new deal, the spokesman added.

In his reply, Stephen Jones, the chief executive of UK Finance, said customers of inactive lenders and firms not authorised for new mortgage lending will be contacted by their mortgage administrator later this year.

The letter added: "At that point we anticipate there will be a range of products from a variety of lenders available.

"Customers will need support in understanding and making their choices, " said Mr Jones.