Leaders of a million businessmen and women who work from home have attacked plans to deliver post later in the day and end second deliveries.

The Royal Mail said the changes, to be tested in Crawley and 13 other areas, will mean a single delivery arriving by lunchtime.

The plans, due to be extended across the country from the autumn, are expected to lead to job losses among postal workers.

The Royal Mail said it was reviewing its delivery services in a move to increase efficiency as more of its markets were opened up to competition.

But the Federation of Small Businesses said people who worked from home relied on early delivery of cheques and vital letters such as orders.

Spokesman Stephen Alambritis said: "We are very concerned that the Post Office is preparing small businesses for what will be a second rate service.

"This is very worrying news."

A Royal Mail spokesman said change was necessary to safeguard the future of an affordable next-day delivery service for everyone.