By Andrew North
BBC News, Basra
British officers have expressed serious concerns about the commitment of Iraqi troops they are training for the new US offensive in Baghdad.
Their comments underline the scale of the challenge in making the new security plan for the capital work and continuing problems building up the new Iraqi army.
Iraqis soldiers being put through their paces by UK officers
The BBC has learnt that the British military is preparing up to 1,500 Iraqi soldiers for service there - a deeper level of involvement in the US security push in Baghdad than previously acknowledged.
Additional Iraqi units are seen as critical to the plan's success. The lack of Iraqi troops available for last summer's security push in Baghdad - Operation Together Forward - was a key reason for its failure.
The new strategy calls for even greater numbers of Iraqi soldiers.
British defence officials admit a failure in Baghdad could have knock-on affects on security elsewhere - including in Basra - possibly affecting British plans to start withdrawing troops this year.
The UK is currently considering handing over more areas of the south, including parts of Basra, to Iraqi government control.
Two battalions from the Iraqi army's 10th division based in Basra have been earmarked for possible deployment to Baghdad.
The soldiers are being given additional training in urban warfare techniques by British and Iraqi military instructors at one of the UK bases in Basra.
The BBC saw some of these preparations during a recent visit by UK Defence Secretary Des Browne.
But during a briefing by British officers, Mr Browne was warned "the precedent for all this is not good".
Colonel Stephen Kilpatrick told him the same battalion being trained now was asked to send troops to Baghdad for last year's Operation Together Forward "and effectively they mutinied".
Shots were fired at the commanding officer's car and they did not get there.
The colonel said measures have been taken to ensure this would not happen this time.
Tribe and family
One problem last year was that "breadwinners from the same family" were called to deploy together, said spokesman Maj David Gell.
The soldiers were concerned their families would suffer while they were in Baghdad, because of difficulties in getting money to them.
Like many Iraqi army units, this one is largely made up of soldiers from the same area, with close tribal and family ties.
That has often made it difficult to deploy them outside their "home" areas.
Des Browne, UK Defence Secretary, gets briefed in Basra
But talking to officers at the base, it was clear that similar concerns remained and that there could be problems getting these troops to the capital again.
Many of the Iraqi soldiers are not showing up for training. Numbers are down from 90 to the low 50s in groups at some sessions.
"You hear things like: 'We don't need to come this week, because we had training last week'," said one officer.
And there is definite reluctance among the soldiers about a Baghdad deployment.
"On the surface, they'll leap up and down with their weapons and say we're going to Baghdad," said Lt Col John Stroud, chief-of-staff for the training mission.
But, choosing his words carefully, he added: "We need to harness that enthusiasm and actually get them on the buses to Baghdad.
"I think we can deliver a force to Baghdad; the size of it remains to be seen."
Maj Gell says the eventual number of Iraqi troops to be sent to Baghdad from Basra has still not been decided, nor when they will go.
But in Baghdad, commanders need every soldier they can get if they are to be able to hold neighbourhoods that have been secured.
While helping out with training for the US security push in the capital, British commanders and politicians also face critical decisions in the south.
The situation in Basra still remains difficult, but the three-month old Operation Sinbad aimed at boosting security has made progress.
However, British bases in and around the city are still being attacked on a daily basis. One base was hit by 28 mortars in one night last week.
Despite this, the British government wants to start reducing troop numbers this year.
But there has been recent US pressure on the British to keep them at their current levels of around 7,200 while the Baghdad plan gets under way.
The US military is concerned partly for the security of its key supply routes through the south, but also over the possibility of the situation deteriorating in Basra if things go awry in Baghdad.
The British deny any rift with the Americans but play down such concerns.
Officials say they doubt there will be a backlash in Basra, but say they have not yet made any decisions on force levels.
But with the defence secretary's announcement of another troop increase for Afghanistan, the British military is now under even greater pressure.
At the moment, plans to transfer another province, Maysan, to the control of the Iraqi authorities have been put on hold, contradicting predictions last year by the foreign secretary that this would happen by the end of January.
Two other more stable provinces in the British south-eastern area were transferred last year.
British officials say they are still concerned that the situation in what one called "the south Armagh of Iraq" could deteriorate.
There were serious clashes late last year in Maysan's main city, Amara, involving rival Shia militias.
One official told me that "a political judgement still has to be taken over Maysan".
But the British want to go ahead with plans to hand over the Shaiba logistics base on the edge of Basra.
And they are considering proposals to start transferring parts of the city of Basra to the Iraqi army and police.
This could allow British troop reductions.
If the new Baghdad security plan doesn't work though, all these plans could change.