By Nick Assinder
Political correspondent, BBC News website
Home Secretary John Reid is investing a huge amount of his own political capital in the decision to split his "dysfunctional" department in two.
He believes the current Home Office is far too big and unwieldy and that separating out responsibility for justice and for security into two distinct departments ministers will be able to get a proper grip on them.
John Reid is accused of rushing through reform
Specifically, as he told MPs in a sometimes heated Commons debate, he believes the terrorism threat requires a powerful new unit within the Home Office able to "focus" its attention on combating that threat rather than being distracted by issues of justice like sentencing and probation.
His critics, however, have warned that the effect of this split will actually be to exacerbate the problem at the heart of the Home Office's woes - that there is inadequate co-ordination between the different sections.
If the left hand already does not know what the right is doing, sticking them on different people's arms will only make matters worse, they claim.
The first row came after the Tories forced Mr Reid to the Commons to make an emergency statement on the proposal amid claims the Home Secretary was revealing it on the day MPs left the Commons for a two week Easter break, so avoiding proper debate.
And there were serious concerns being raised over the proposal from all sides.
Former Home Secretary Charles Clarke went so far as to brand the move "irresponsible", which led to a slap down from Mr Reid, accusing him of having got things wrong during his time in the job.
Home Office was deemed not fit for purpose
Shadow home secretary David Davis said the move would distract the departments for months and end up with even more problems with crime, immigration and security.
"Because of the way it has been done, the creation of a department of justice and a department of security will leave public security undermined, and a justice system overwhelmed," he said.
He also repeated the suspicions voiced elsewhere that the decision was a botched job after a row between ministers over who controlled what.
The Liberal Democrat's Nick Clegg also highlighted what is believed to be the underlying politics of the decision, claiming it is being rushed through by Mr Reid and Tony Blair before Gordon Brown - thought to be lukewarm, at best, over the proposal - becomes prime minister.
He also noted the fact that an inquiry into the 7 July bombings had been rejected on the grounds it would distract attention from the fight against terrorism.
Would not, he asked, the time and effort taken in arranging the department's split be greater than holding a public inquiry would have taken up.
There is a suspicion already running around Westminster that Mr Brown may want to take an entirely different approach to the Home Office.
Mr Blunkett opposes Home Office split
It has previously been suggested, for example, that he wanted the anti-terrorism effort concentrated under the cabinet office.
Since Mr Reid's split plan was originally floated former Labour home secretaries have confirmed they also considered such proposals while in post, but rejected them.
Jack Straw said he opposed the idea when he ran the department, saying he felt he could cope with the department's broad range.
But he said he had changed his mind as a result of the huge growth of terrorism and counter-terrorism as an issue since the terrorist attacks on 11 September.
His successor, David Blunkett, also dismissed such suggestions and still opposes them, warning the "Balkanisation of government" - with departments led by a number of ministers - would inevitably concentrate power into the hands of the prime minister and chancellor.
But this has now become Mr Reid's big idea and, if he remains as home secretary, as expected, under Gordon Brown's likely premiership he will feel the full effects of its success or failure.