By Nick Assinder BBC News Online political correspondent

Brown has little to smile about

So the prime minister's decision to appoint the man dubbed his personal attack hound to the job of sorting out the NHS sends out some pretty tough messages.

It tells the public sector in the clearest possible terms that the government will not be backing down on its reforms, notably the creation of foundation hospitals.

It sends precisely the same message to rebellious backbenchers who have been threatening to challenge the government over the highly-controversial policy.

And, far more significantly, it tells Gordon Brown that he faces a bare knuckle fight if he attempts to further limit the prime minister's reform package.

Any suggestion that the prime minister and the chancellor are not locked in a bitter battle over the direction of the government will be blown away by this appointment.

Bed of nails

It also suggest Mr Blair believes that, while he is not powerful enough to move or sack his chancellor, he is determined to finally clip his wings.

The announcement came amid speculation that, following the shock resignation of Health Secretary Alan Milburn, the prime minister had found it difficult to get anyone to take on this particular bed of nails.

In fact the prime minister made the decision to hand the job to Mr Reid at the beginning of this week - possibly only hours after Mr Milburn had offered his resignation.

Meanwhile, the retirement of controversial Lord Chancellor Lord Irvine and the abolition of the historic post will cause little sadness in the palace of Westminster.

His reputation for expensive tastes - most notably on the refurbishment of his official apartment - and lofty attitude has not made him popular either inside or outside parliament.

He will be replaced by another of Tony Blair's close friends, Lord Falconer, in what amounts to a new justice ministry.

Gloves off

Mr Reid has now held a series of government jobs, most recently as Leader of the Commons, but with one clear brief - to get stuck in on behalf of his boss.

He is fiercely loyal and a formidable, even intimidating operator.

Just how his appointment will go down in the NHS remains to be seen although it is unlikely the unions will be delighted by it.

Gordon Brown, who has previously seen his faction in cabinet decimated will also be dismayed.

To all intents and purposes this is now a gloves off fight.

Meanwhile, Home Secretary David Blunkett also failed to stop a large chunk of his department being split away into a new ministry charged with overseeing the judiciary.

Rocky road

Mr Blunkett has no love of judges who he all too often believes are failing to adopt his tough policies.

He is said to have resisted losing the responsibilities, but pressure has long been building on the prime minister to create a separate ministry of justice.

That is, in effect, what he has done with the new Department for Constitutional Affairs.

It also takes in responsibility for Wales and Scotland - the abolition of full departments long seen as inevitable in the wake of devolution.

The casualty for all that has been Helen Liddell who has not been deemed a particular success

This may not have been the largest reshuffle in terms of numbers, but it is hugely significant.

Dr Reid's appointment, in particular, signals a rocky road ahead for the government and the prime minister's determination to end the delays and fudges around public sector reform.

The great fear must be that he may actually have made matters worse by taking such an aggressive attitude.