By Stephanie Todd BBC News Online

Thousands of customers will be affected by a price rise

It took the unusual step of criticising a private sector company following an announcement by British Gas that it is to increase prices.

However the Scottish Tories believe the executive should not concern itself with private sector pricing.

A spokesman said: "If Marks & Spencer raise their food prices, will the executive get involved too?

"This is an issue that has nothing to do with politics.

"I think it's inappropriate for them [the executive] to be making a comment as far as Scottish Gas is concerned.

"There are many occasions where politicians comment on issues they shouldn't and this is one of them.

"People realise there are different energy suppliers out there, they don't need politicians telling them what they should and shouldn't be doing."

'Ambitious targets'

He added: "There is plenty going wrong in Scotland that the Scottish Executive would be far better off diverting its time towards."

Scottish Gas announced on Wednesday that prices will go up by 12.4% for one million residential customers, with 500,000 residential electricity customers seeing bills rise by 9.4%.

The company blamed the depletion of North Sea and Irish Sea gas reserves.

Shortly after the announcement was made, the executive released a statement encouraging Scottish Gas customers to shop around for a better deal.

We are not telling anyone who to enter into a fuel supply contract with, but think it is important that people are aware of the benefits of shopping around Scottish Executive

A spokeswoman said: "Scottish Gas should have discounted the rate for Scottish customers. We urge everyone to shop around to get the best energy deal possible."

Energywatch Scotland, the independent gas and electricity watchdog, also hit out at Scottish Gas, but admitted that it was "the first time the executive has came out and said that people should switch away from a company".

Speaking on BBC Radio Scotland, spokesman Graham Kerr said: "I'd imagine the executive is devastated by this.

"It has very ambitious fuel poverty targets and wants to eradicate fuel poverty in Scotland over the next 20 years.

"It has invested so much money to achieve that and then a private company comes along, hikes up their prices and makes the executive's job almost impossible."

Alan Hogarth, spokesman for CBI Scotland, declined to comment on the executive's statement.

He said: "Obviously it is a competitive market place and consumers have a wide variety of companies to choose from."

Responding to the Scottish Conservatives' claim that previous comments were "inappropriate", an executive spokesman said: "We are not telling anyone who to enter into a fuel supply contract with, but think it is important that people are aware of the benefits of shopping around. "

A spokesman for rival energy firm Scottish Power said it had been inundated with calls from customers looking to switch following the price hike by Scottish Gas.

He said: "We recorded an increase of between 20% and 25% of calls since the announcement from Scottish Gas and I can safely say the majority were from homeowners inquiring about the possibility of switching their energy supply."