Eurosceptic: Teddy Taylor will speak at protest

The euro replaced national currencies in 12 of the 15 EU countries on New Year's Day.

Jim Reynolds - one of the organisers of the City protests - said campaigners were fighting the belief that the euro would inevitably be taken up by the UK.

"Our main concern is actually loss of control. We would no longer have control over our interest rates, taxes or fiscal policy," he said.

'Euro not right'

"This would be left to unelected people in Germany and of course the European Commission."

Earlier, Conservative Party chairman David Davis said up to 70% of British people were still against giving up the pound, saying Britain - as the world's fourth largest economy - should retain control of its economy.

"It's not right for Britain, certainly not for the foreseeable future as we can see, because it is fundamentally flawed," he said.

"It's a problem that you have a one-size fits all interest rate across Europe."

Europe minister Peter Hain has denied that he regards British membership of the new currency as inevitable.

Poor exchange

He earlier suggested there was little doubt that Chancellor Gordon Brown's economic tests for entry would be met at some point, triggering a referendum.

But he later said he did not want to pre-empt the assessment the chancellor is set to complete in the next 17 months.

Sir Ken Jackson, leader of the Amicus union, urged ministers to hold the vote as soon as possible.

"With the uncertainty that is around people are not making long term plans. Investment is falling in Britain - France has overtaken us now as the leading investment area for Europe and, of course, we are suffering from that," he said.

Shadow chancellor Michael Howard said the government was "at sixes and sevens" over British membership of the euro.

"The government should stop playing games over the euro. If it thinks we should go in it should say so and hold a referendum," he said.

"If it doesn't, it should say so and concentrate on dealing with the crisis in public services, which gets worse by the day."

Consumers are afforded few opportunities to use the new currency in the UK and may be charged handling fees and poor exchange rates.

A spokeswoman for retailer WH Smith said selected outlets which accepted payment in foreign currencies - including the euro - routinely charged a handling fee of about 8%.