We have proved on numerous occasions that we are the most efficient provider of service to the fleet, and the decision is a slap in the face

Alan Grey, union official

The strike prompted an appeal for conciliation from Armed Forces Minister Adam Ingram, who said a number of issues raised by the unions had been taken on board and would be discussed.

Blue collar workers are expected to support further industrial action at the base in the campaign to force the government to reverse its plans.

Mr Grey said he believed the unions' public sector alternative to the government's plans had not been given sufficient examination.

He said: "It is a business case which we believe is the result of a biased approach, a dogmatic approach and we tried to put a public sector alternative.

Adam Ingram: Understood the strength of feeling

"But we don't feel that we got a fair hearing.

"We can deliver more and better and we doubt very much the figures that the MoD is quoting."

"We are very pleased with the turnout and the support we are getting from our members and other unions.

"It looks as if a lot of people have simply taken the opportunity to stay at home and not cross the picket line."

Mr Grey said workers were sending a clear message to defence ministers and the MoD over the proposals.

'Strength of feeling'

Mr Ingram said the government had taken on board the workers' feelings and he would meet unions to try and assuage their concerns.

"Clearly I understand the strength of feeling which is amongst the workforce," the minister said.

"I had a very useful and productive meeting with the unions earlier this week and we are now looking at some of the issues that they raised with us.

"We are putting in place a series of meetings between officials and myself to seek to find answers to that."

One picket donned a Tony Blair mask

Three hundred of the striking white-collar workers took part in a march through Helensburgh on Friday.

Speaking at the rally, David Luxton, of the non-industrial union Prospect, said: "Support for the strike today, overwhelming support, reflects the anger, dismay and uncertainty on the Clyde."

Ralph Groves, of the Public and Commercial Services Union (PCS), said its members were striking because they felt "betrayed by the government and the MoD".

Plans for "partnering agreements" with the private sector were announced by Mr Ingram last month.

Private firms

They will affect the Clyde bases and the naval installations at Portsmouth and Devonport.

A total of about 3,000 workers will have their work switched to private naval dockyard firms in a scheme aimed at saving the taxpayer more than �300m over five years.

However, the minister warned of the prospect of job losses, with the majority expected to go on the Clyde.

About 1,700 Scots workers are affected

The MoD has stressed that the plans mean "industrial partnering" rather than privatisation.

Commodore John Borley, director of the Clyde complex, said the action by office and administrative staff was "in no-one's interest, least of all the workforce at the base".

He said: "It is a pity that an element of the staff has chosen to follow this path.

"I would like to see management, staff, unions and our future partner working together to build a strong future for the base and that will not be achieved by strike action."

The MoD said that Britain's nuclear deterrent of Trident missile submarines, based on the Clyde, was not adversely affected by the action.

The defence unions plan to hold mass meetings in Portsmouth and Devonport next week.