Tories in election plot to boost IDS

The Conservatives are privately suggesting they will win at least three times as many local government seats as their official prediction of 30.

Party sources have revealed that the deliberately low figure had been chosen to ensure the real outcome appeared to be a triumph against expectations for Iain Duncan Smith, the future of whose leadership is widely believed to rest on the 1 May poll.

Predictions of gains of 100 seats or more were "closer to the mark", a Conservative source said, following the advances made by former leader William Hague in the local elections four years ago. He added 1,300 seats to the Tory tally. "While we don't expect to hit the sorts of figures that Labour and the Liberal Democrats are talking about, put it this way, we'll be disappointed if it is 30."

The local election campaign will be relaunched by all three major parties this week after the initial start was overshadowed by the war in Iraq. Mr Duncan Smith will spend the week campaigning in Scotland and Wales, where there are elections for the devolved authorities, and in Shropshire.

The Tories will be campaigning on local issues with an umbrella theme to draw attention to large council tax rises, particularly in the south of England. They aim to target Labour councils in Basildon, Worcester and the Medway towns, to cling on to newly acquired councils such as Amber Valley, and to take on the Liberal Democrats in Poole and Harrogate. The Tories believe Labour will be hardest hit by the election result but perceive a threat from the Liberal Democrats. And it is the Liberal Democrats that Labour will attack in this first week of sustained campaigning.

At an event this week in Sheffield, where there is a straight fight between Labour and the Liberal Democrats, Labour's new party chairman, Ian McCartney, will say there is a "clear dividing line" between a Labour Party that invests in public services and a Tory party "committed to 20 per cent cuts in public spending ... Where the Lib Dems are the main challenger we will be highlighting their record of broken promises and failure to deliver on issues that matter to local people, such as anti-social behaviour."

Some commentators predict Labour could profit from the war in the Gulf. According to anti-fascist campaigners, the threat of the British National Party, which is set to field a record 219 candidates in next month's elections, has been undermined by the war.

Searchlight, the anti-fascist campaign group, said the BNP was "pushing hard" to extend its support base from North-west towns to other areas – Stoke, the Ribble Valley, Pendle, Wigan and the North-east. The party is putting up a full slate of 25 candidates in Sunderland.

Nick Lowles, a spokesman for Searchlight, said: "Though Labour risked alienating its own voters over the war, young working-class males aged between 18 and 35 – the group most likely to support the BNP – support the war. There is evidence that some of them are coming back."