Instead, the country will send additional troops to reinforce NATO operations in Afghanistan.
The UK had been considering sending up to 3000 extra troops to Iraq to replace departed Spanish and Polish forces, and had been due to extend operations beyond its current base in the southern city of Basra.
Part of this deployment would have involved moving a major, British-run NATO command post from Germany to Iraq.
However, mounting concerns from lawmakers in Prime Minister Tony Blair's ruling Labour party about how unpopular this would be with voters, still deeply sceptical about the war in Iraq, led to the plan being dropped.
The BBC has reported that a significant number of British troops, as well as the command operation, would instead be sent on the more "politically palatable mission" of Afghanistan.
However, British Foreign Secretary Jack Straw said that while there were no immediate plans to add to the 9000-plus British forces currently in Iraq, this could change.
"The truth is that these things are, really, kept under review day by day, week by week," he said when asked if no more troops would be sent.
Foreign Secretary Jack Straw
says plans change day to day
"Overall, however, a decision has been made for the time being - and I can't say whether that's days or weeks or months - that the current level of troops is adequate," he said.
Straw also denied that British soldiers were about to be pushed up from Basra into the city of Najaf, south of Baghdad.
"That isn't happening at the moment. Whether there is a need to will depend above all on requests of the Iraqi interim government," he said.