LONDON / Major calls for Serbia blockade: As the ravaged town of Srebrenica comes under heavy shelling, the world's politicians debate its future

JOHN MAJOR yesterday called for an early blockade of Serbia after bilateral discussions with President Francois Mitterrand led to mounting diplomatic pressure on the Serbian leadership.

As opposition leaders and Lord Owen, the EC peace envoy, called for consideration of punitive air strikes on Serbian supply lines, senior government sources said economic sanctions were being given one last chance. Mr Major will talk today to President Bill Clinton as the US administration also shows signs of moving towards advocacy of air strikes.

Mr Major, still reluctant to back the use of force, urged the UN Security Council to bring forward discussion of a motion detailing tighter sanctions on Serbia and last night the council began meeting in emergency session at the request of the French.

Britain hopes for early enforcement of a blockade, a matter that was to have been delayed until after President Boris Yeltsin's referendum in Russia on 25 April.

In language reflecting a toughening Downing Street stance, a statement said that 'all possible steps must be taken to protect the population of Srebrenica'. It added: 'The international community should act physically to prevent breaches of sanctions by land, sea and river, and to seek to enforce financial sanctions.' While Britain does not envisage deploying more troops to enforce the blockade, equipment may be made available. Ministers would like to see stricter search and arrest operations on river, land and sea frontiers.

Financial sanctions are expected to figure prominently in the new pressure against Serbia, with particular anger directed against Greece and Cyprus, which British officials accuse of lax enforcement. Measures may be taken to ensure that assets across Europe can be frozen.

Western diplomats were clearly hoping that an increase in diplomatic pressure would prevent the Serbian forces from entering Srebrenica. There were hopes that the latest aggression had even angered Serbia's closest ally, Russia, to which undertakings were said to have been given. That could change the balance at the Security Council, where Western powers have been anxious not to push the Russians too far, ahead of the referendum.

At home, the growing clamour for air strikes appeared to take the Government by suprise. Advocates of the use of air power argued that the consequences of the loss of humanitarian aid that would involve would be less severe now the winter was over. Lord Owen, who also urged the speedy passing of the UN sanctions motion, argued for UN backing before air strikes were mounted on Serbian supply lines. He added: 'They would have to be done with care as there could be civilian casualties, but that danger only becomes greater when you try to take out heavy weapons.

'The argument that you need land forces is not correct, because the Muslims and Croats are on the ground. This could tilt the balance and bring pressure on the Serbs to sign up to the peace settlement.' The Vance-Owen plan would divide Bosnia-Herzegovina into 10 largely autonomous provinces.

Underlining Labour's hardening position, John Smith, the party leader, told BBC Radio: 'We cannot stand idly by and watch this continue. What has happened now, it seems quite clear to us, is that relying on economic sanctions alone will not be enough in this situation. It is time for us to consider punitive air strikes upon the lines of communication of the Serbs, with the effect of halting their advance.'

Later, at Labour's South-west regional conference in Weston- super-Mare, Mr Smith said: 'I believe it is now necessary for the UN to issue an ultimatum to Serbia - that unless a ceasefire is made effective the UN will authorise air strikes against Serbian lines of communication in Bosnia-Herzegovina.'

The Liberal Democrat leader, Paddy Ashdown, said: 'The only solution to this problem will come in the UN defending Muslim positions and this can be done . . . within our present mandate and without changing the terms of engagement of UN forces.'

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