By John Pienaar BBC News political correspondent

Day by day, the government has been forced onto the defensive on the issue that was once Labour's home territory: public services.

The Cardiff conference this weekend marks the latest attempt by senior ministers to regain lost ground.

Blunkett: Government needs to empower local people

No-one doubts the state of public services is the defining domestic issue of Labour's second term.

Tony Blair underlined that basic truth last weekend, volunteering in a newspaper interview to face the voters' verdict if services like the NHS were not "fixed" in time for the next general election.

It was a bold claim, and one that could echo loudly through the next election campaign.

Limits to power

In Cardiff ministers, are trying to set the terms of the debate ahead.

The Home Secretary, David Blunkett's contribution looks significant.

Like other ministers, he is emphasising the importance of investment linked to reform.

But he is going further; identifying the limits of government power as well as its extent.

He is known to feel, for example, the public are sometimes too willing to blame the Government for levels of crime, and too willing to overlook the fact that the police operate independently.

Mr Blunkett also believes his colleague Stephen Byers, the Cabinet minister in charge of transport has been unfairly blamed for the current spate of rail strikes.

'On your side'

The speech is bound to be seized on by Labour's critics as an attempt to shirk political blame.

Recent opinion polls suggest growing dissatisfaction with the government's stewardship of public services.

The Home Secretary is clearly attempting to redefine the terms of the debate; to convince the public that blame should focus of those who bear direct responsibility - rather than automatically descend on the party in power.

John Prescott will defend PPP investments

Instead, he conjures the notion of an "on your side" style of government, in which ministers help enable individuals and organisations improve conditions locally.

On another front, ministers are anxious to calm the perception of confrontation with public sector workers.

Last week, Tony Blair went out of his way to reassure staff in the NHS and other services that his Government was their ally, the Tories their enemy.

That is a theme taken up by the Deputy Prime Minister John Prescott, in his address to the conference.