How banks aim to cash in on the postal strike by hitting customers with penalty fees

The banks, which are in line for a huge windfall, have indicated there will be no leeway or period of grace because of the strike.

This is likely to mean many customers will not get credit card statements and utility bills as expected.

The banks insist they should take steps to find out how much they owe on their cards and make a payment by the normal monthly deadline.

A failure to make the minimum paycouldment would leave customers open to a fine of £12 each.

They could also end up paying extra interest on the bills.

The first 48-hour postal strike finishes at noon today, while a second is due to start early on Monday.

The banks' trade body, the Association for Payment Clearing Services, hinted at the imposition of late payment fines, saying the strike means "important post could be delayed that could have a knock on affect on finances".

It warned: "Although your bill may not arrive in the next few days, you shouldn't assume that payment isn't due within the normal timescale.

"Anyone who is due to pay a bill by cheque in the post during the strike should check they are not going to miss a payment deadline and be penalised as a result."

Customers also find themselves paying penalty charges to their suppliers if they fail to pay their utility bills by the deadline.

Eddy Weatherill, of the Independent Banking Advisory Service, criticised the banks, saying: "It is only the banks who would look to cash in on a national strike which is causing huge disruption.

"It is typical that they view every crisis as an opportunity to make money."

A war of words broke out yesterday between the Royal Mail and the Communication Workers Union over the impact of the strike, which began when staff walked out in dispute over pay, pensions and a reorganisation scheme that will cost 40,000 jobs.

Royal Mail chiefs claimed the strike was crumbling, with 35,000 staff turning up for work as normal during the first 24 hours of the stoppage. That is around a third of those who were due to be at work.

A spokesman said: "We are continuing to process mail and deliveries are taking place across the country, albeit at reduced levels."

The union claimed "overwhelming" support from the public, saying a poll it commissioned of 1,000 adults showed more than two-thirds backed its campaign over pay and conditions.

Royal Mail announced it has agreed a deal on pay, pension reform and modernisation with the Unite union, which represents 12,000 managers.

The company is trying to agree a similar deal with the CWU in talks which are expected to continue over the weekend.