The Communication Workers' Union (CWU) has announced a vote in favour of strike action. Although the Royal Mail is believed to have contingency plans to stop the service grinding to a halt, small business groups are still very concerned.

The Federation of Small Businesses (FSB) told The Independent that smaller firms often work to tight margins and they could be tipped over the edge if they face delays in receiving payments.

It added that some firms were sending out invoices early or asking creditors to make payments directly into their bank accounts.

The CWU is in dispute with management over a pay claim.