Consumers could end up paying more money to withdraw their own cash after two of the biggest providers of fee-paying ATMs agreed to join forces in an £87.3 million deal, it has been claimed.

The proposed tie- up - accounting for around a quarter of all fee-paying ATMs in the UK - involves an all-share offer for Moneybox by its similar-sized rival Cardpoint.

More than 5,000 cash machines will be involved, a figure which could rise under expansion plans previously announced by Cardpoint.

The two companies said a deal made sense as a large number of companies were now operating in the sector and causing increased competition for prime sites.

But concern was raised about the deal by Nationwide, which has been campaigning against charging ATMs. Moneybox charges between £1.50 and £1.70 to withdraw cash.

A spokeswoman for the building society: "We are not saying it is wrong to charge per se, there are places it would not be commercially viable to have a free machine.

"But people work hard for their money and should always have free access to it. Even if there are charging machines in places like pubs, where people might not want to go out and walk to an ATM, you should still have a choice."