The Scottish secretary and the Welsh first minister have waded into the row over euro membership.

Helen Liddell said that the chancellor's vaunted five economic tests were not an "exact science".

And Rhodri Morgan said that previous high Sterling valuations had imposed a "crippling burden" on businesses in Wales.

Speaking on Monday, the Scottish secretary said staying out of the euro would have serious consequences.

Liddell told business leaders that she was setting out an "extension" of the five tests by urging consideration of the impact on jobs and inward investment if Britain remains outside the single currency.

"We could have a situation where we have a single market with 25 countries, 24 of them in one currency and one in another and I worry about the consequences of that for Scotland."

And while Gordon Brown has insisted his analysis will be based on a rigorous economic analysis, Liddell described the tests as "not an exact science, it's all about the balance of probability".

Also speaking on Monday, Rhodri Morgan said that Welsh business leaders should make sure their views are heard in the euro debate.

"The issue of the euro is starting to heat up," he said.

The first minister said business chiefs should think about what exchange rate they would like to join the euro at.

"Now it's on the possible agenda, you have to consider what would be a competitive rate for your business. Would it be 75 pence to the euro, or 80 pence? What's reasonable for Welsh business, if the political decision is made?

"I have no inside knowledge, but the situation is going to heat up once the Treasury report is published on the five tests," Morgan said.