About 100 soldiers from a largely Welsh regiment are preparing to support fellow British troops being redeployed in central Iraq.
It is the second time the Welsh Cavalry has been in Iraq
Soldiers from The Queen's Dragoon Guards - the Welsh Cavalry - are reported to be supporting 500 soldiers from the Black Watch in the US sector.
Controversy has surrounded the decision to send British soldiers to the region.
But Defence Secretary Geoff Hoon said the redeployment of British troops would last "weeks rather than months".
Welsh Labour MP Dai Havard, a member of the defence select committee, said the area to which the British troops were being deployed was more dangerous than their present base in Basra, southern Iraq.
Mr Havard, the MP for Merthyr Tydfoil and Rhymney, added: "Basra and those provinces down there are not an easy piece of ground - it's dangerous.
"This is potentially more dangerous because in the south they are in a Shi'ite majority area, they are moving to a Sunni area.
"I am not terribly exercised that we shouldn't move into different areas. That's not the question - my question is the purpose of doing it.
"How does it contribute to the end game? How does it get us the peaceful stable democratic Iraq we say we all want?
"We are going to have troops in there for a long long time and there will be other movements.
"We have to have a way of seeing that we are actually going to do what we declared we wanted to do, which is to help the Iraqis build this peaceful state within its current borders."
The Welsh Cavalry armoured reconnaissance unit which could be sent to support the Black Watch will consist of 100 men and 12 Scimitar armoured fighting vehicles.
The redeployment was announced by Mr Hoon on Thursday after ministers agreed to a request for support from the US.
The Welsh Cavalry are undertaking their second tour in Iraq
Simon Pearson, who runs military consultancy BH Parners, told BBC Radio Wales he believed the US required support in some of the areas under its control in preparation for a planned assault on the insurgent stronghold of Falluja.
"What the Americans are preparing for is a four to five week assault on Feluja.
"They've puled out 800 to 1,000 combat troops to go and deal with that.
"Felujah lies 35-40 miles to the north west of Iskandariya which is where I understand the Black Watch and the Queen's Dragoon Guards are going.
"Thee's no doubt we are getting slightly deeper into it.
"The military planners will have done an assessment which would have said that we need some light armoured support and that's where the Queen's Dragoon Guards come in.
"I think they are being put slightly more at risk than they are in Basra. But from what I hear morale is very high and they are looking forwad to it."
Preparations for the redeployment have been under way at the Black Watch's base in Basra for several days.
The Welsh Cavalry, which has its home at Maindy Barracks in Cardiff, recruits mainly from Wales, Herefordshire and Shropshire.
They are undertaking their second tour of duty in Iraq.
During their first tour, which ended earlier this year, reconnaissance tanks from the Queen's Dragoon Guards were at the spearhead of British operations around Basra.
Members of the regiment were rewarded for their efforts in destroying more than 20 Iraqi tanks by being presented with the Commando dagger by the Royal Marines.