The UK is preparing the ground to call up reserve forces in preparation for possible war with Iraq, defence secretary Geoff Hoon is to announce.

The Ministry of Defence is believed to have begun consulting employers about reservists - which means that when the time comes for a call up, it can happen more quickly.

Hoon: Will not confirm numbers of reservists needed

Mr Hoon will make the announcement during a House of Commons debate on the Iraq crisis later on Monday.

Tony Blair's Labour Government is braced for a sizable protest from some of its own MPs, who want an assurance that no military action will be taken against Iraq without explicit UN clearance.

They want to add amendments to what they say is a "bland" motion - which asks MPs to back the current UN resolution on weapons inspectors.

Reticence

Last week, Mr Hoon confirmed that Britain had received a request for troops from the United States.

BBC defence correspondent Paul Adams said American war preparations had been fairly conspicuous, compared to the British Government's reticence.

Hostilities - if they occur - are believed to be most likely to start in January or February.

Depending on the size of any British force, thousands of reservists will be needed, either for operational duties or for what's known as back-filling - taking over duties from units that have been sent abroad.

Alleged weapons

Defence sources say Mr Hoon will not be drawn into numbers, or say when reservists will actually receive their call-up papers.

Iraq has until 8 December to disclose details of its alleged weapons of mass destruction.

But political leaders on both sides of the Atlantic do not anticipate receiving a truthful account.

However, service chiefs have long complained about UK troops being overstretched.

Last week, Admiral Sir Michael Boyce, chief of the defence staff, raised concerns about shortage of manpower.

He said the pressure of providing army personnel to provide emergency cover during the ongoing firefighter's strike would cause "extreme difficulty".

Mr Hoon insisted Sir Michael had explained the services would be able to manage many different commitments.