A surprise council by-election victory for the far-right BNP means the main parties must do more to promote racial tolerance, says Foreign Secretary Jack Straw.

The win in Blackburn, Lancashire - Mr Straw's constituency - adds to the three seats the British National Party already holds in the north west of England.

Candidate Robin Evans won the Mill Hill seat in Blackburn with a majority of just 16 votes.

The seat on Darwen Borough Council became vacant after a Liberal Democrat councillor left the area.

There were angry scenes even before the count took place at the old town hall in Blackburn.

The politics of racial exclusion can have no place in British society

Jack Straw Foreign Secretary

Between 30 to 40 demonstrators shouted insults at the BNP candidate and his supporters as they entered the building.

After a tense recount, the BNP took the seat with 578 votes to Labour's 562, the Lib Dems 505 and the Conservatives 154, with turnout at 39%.

The election saw Mr Straw campaigning for Labour.

Afterwards he noted that twice as many voters had voted for other parties as for the BNP.

"This result will not obstruct our efforts to build a more tolerant, multi-religious community in the town," he said.

"The politics of racial exclusion can have no place in British society and all mainstream parties and politicians will now have to work harder to defeat it."

'Neglected majority'

Successful candidate Mr Evans said: "I do not just regard this as a victory for myself and the Blackburn BNP.

"It is an important victory for a long neglected majority in other wards in Blackburn who now have a voice in me."

Blackburn has a large Asian community but has avoided the racial tensions seen in other parts of northern England.

Race tensions saw rioting in summer 2001

Politicians, trade unionists and community leaders last month began a campaign to unseat the BNP's three councillors in Burnley.

Their election came after inter-racial rioting in Burnley and other towns in the North West in summer last year.

The BNP still only has a toe-hold in the north-west, but the latest result will worry the mainstream political parties.

The official report into the violence in June 2001 said organised white racists had exploited clashes to exacerbate tensions and fears.

It urged the government to tackle "shockingly" divided communities in Bradford, Burnley and Oldham, which have large British Asian communities.

Previous campaign

But the BNP has said its election success stems from the marginalisation of white residents by the main political parties.

The four councillors now in office are the BNP's only success on local councils since the short-lived election of Derek Beackon in Tower Hamlets, London, in 1993.

A campaign by politicians and activists helped to unseat the councillor.

Elsewhere on Thursday night, the Tories lost their overall majority at Dacorum Borough, Hertfordshire, when Labour gained a Woodhall seat.

Labour narrowly kept its overall majority at Bolton Borough, Greater Manchester, when it won at Daubhill.