The Royal Mail was last night accused of trying to pressure businesses into paying �3,150 a year to guarantee their post will be delivered at the start of the working day.

The Royal Mail was last night accused of trying to pressure businesses into paying �3,150 a year to guarantee their post will be delivered at the start of the working day.

Officials at the Royal Mail's Norwich depot have sent a letter to some businesses saying they "can no longer commit to getting your mail to you at a specific time" without charging a premium for the service.

But "timed delivery" will cost businesses �262.50 a month or �3,150 a year, payable in advance.

A host of small business owners contacted the EDP yesterday to complain that standard free postal deliveries were "erratic", with delivery times varying during the working week.

But they said they would rather "work around" the postal system than pay an extra charge to guarantee early morning deliveries.

"Sometimes the post is here at 8.30am, sometimes you have to wait until later in the day," one small business owner in Norwich said.

"If you're waiting for a quote to come through or a cheque to bank, then it can mess up your whole day."

Last night , the Royal Mail denied it was putting pressure on businesses to pay for a premium service and said the "vast majority of business mail was delivered in the morning".

Anger over the premium service came as it emerged there will be an emergency debate about the future of the Royal Mail at the Labour Party conference tomorrow .

The Communication Workers' Union will call upon ministers to tackle the Royal Mail's multi-billion pound pension deficit.

It also comes as thousands of postal workers continue to take industrial action in a long running row over jobs, pay and services.

About 15,000 workers are due to walk out this week for 24 hours at mail centres across the country, ranging from London and the West Country to Wales and Scotland.

Jeanette Thurtle , East Anglia regional organiser of the Federation of Small Businesses (FSB), said firms should not be asked to pay for getting their mail in good time.

"Small firms are key customers of postal services and FSB statistics show that 70pc of small businesses use the Royal Mail to post invoices and over half send cheques by post," she said.

"These are tough times for business owners and it is no time for them to be left waiting for bills to be paid and money to get through to their own suppliers."

Mrs Thurtle added: "Small businesses should not be made to pay more for a pre-existing service. For Royal Mail to be requesting further payment is another move away from providing a universal service."

Caroline Williams, chief executive of Norfolk Chamber of Commerce, added: "This latest news would seem to pass extra financial pressure to businesses and this coupled with the current industrial action is attracting further uncertainty for the postal service for businesses.

"Reliable and effective communication is essential for businesses and the Norfolk Chamber of Commerce will continue lobbying for this. One of the campaigns we are running is for better broadband capability in Norfolk and this will help businesses look to alternative online methods for banking and communication."

But the Royal Mail said "it remains the case that the vast majority of business mail is delivered in the morning".

"We are absolutely not putting any pressure on customers to pay for delivery of the mail and, of course, Royal Mail's standard six-days-a week delivery service remains free for customers at the UK's 28 million addresses - and there is no intention whatsoever to change that free delivery service to consumers and businesses throughout the country," a spokesman said.

"Royal Mail's Timed Delivery service, which dates back years and has several thousand business customers, offers the option of applying for a specific time for delivery of their mail - from 6am in the morning - and the price reflects the extra work sorting the mail and making a bespoke delivery in addition to the standard free delivery."