SOCIAL Security Secretary Alastair Darling has been handed a new remit to range across departmental boundaries to wage war on poverty, in an appointment by Downing Street which is seen as reining in the power of Chancellor Gordon Brown.

Mr Darling, a high-flier whose talents are well regarded by Tony Blair, relaunched himself in Edinburgh yesterday in a new role which has wide implications for pushing through hard-nosed

benefit reforms.

The event was clearly pitched to maximise the impact on the Scottish General Election in May, but back in Westminster the runes were being read more broadly. ''Tony Blair rates Alistair hugely,'' said one senior Cabinet source. ''He is on-side, reliable, uncomplicated, and ambitious in a healthy way.''

The observation makes a clear contrast with the supposed unhealthy ambitions of the Chancellor, who has been very pro-

prietorial about Scotland in general and the poverty campaign in particular. Now the Chancellor's hitherto unique right to range across departmental boundaries is matched by the new role for Mr Darling.

The Chancellor's supporters were playing down the conflict last night, insisting he would be delighted by the new focus on an issue which has been at the heart of his personal political crusade.

Mr Darling has shunned the title ''Poverty Czar'' which was already being applied to his new role yesterday. Giving every problem or crisis its own Czar is seen as a simplistically cheap shot.

But his aides described a genuinely new and wide-ranging inter-departmental role in which he will demand a wide range of performance indicators relating to unemployment, educational attainment, single-parent households and sub-standard housing.

Mr Darling accepted that this ''poverty audit'' could prove a political hostage to fortune, but he believed that measuring current performance and future achievement was the only way to proceed.

His main speech yesterday to Benefit Office staff at Wester Hailes in Edinburgh was a restatement of recent tough utterances on the rights and responsibilities of benefit applicants. ''I make no apology for this,'' he stressed.

As a result, he was criticised by welfare groups for making ''scapegoats'' of the unemployed. His ''holistic'' approach to stamping out poverty brought a muted response from welfare groups.

Morag Gillespie, director of the Scottish Low Pay Unit, said the Government had to tackle the causes of poverty instead of making those directly affected ''scapegoats'' as a result of changes to the welfare system.

''A more co-ordinated approach to poverty must be a good thing, so long as it tackles the fundamental causes of poverty. One of the concerns we have about this Government is that they tackle the symptoms too much and don't deal with understanding issues.''

Susan Robertson, director of One Parent Families Scotland, said: ''Social Security is such a fundamental part of the whole system, and a lot of problems people have are those created by the social security system. We will be watching with care as to what definitions of poverty are used. We have concerns about the situation of families who rely on income support and the inadequacy of benefit levels.''

Mr Darling remained resolute in his attack on the ''something for nothing'' culture and said people had to be helped to escape from a lifetime on benefits.

''It is clear the welfare state needs a radical reform. Fifty years on, in this the final year of the 20th century, a child can still be born poor, live poor, and die poor. Benefits alone cannot tackle this. It's easy to send out Giros, but a Giro won't get you a job or improve your skills.

''The system has become part of the problem by encouraging dependency by passively paying out benefit. And encouraging people to feel the best they can expect is a lifetime on benefit. It is this poverty of expectation which has to be confronted.''

Mr Darling did not back off from his most controversial insistence, that both lone parents and the disabled must submit to an interview if they are to retain their benefits, although they would not be forced to accept a job.

The SNP's Kay Ullrich said: ''Mr Darling is part of the problem, not part of the solution. It is offensive to hear the vital crusade against poverty made use of for reasons of political spin. What Scotland needs is a real crusade to tackle bad housing, declining public services and the despair born out of an uncaring Government.''