Inside Parliament: Dissenters raise the Balkan question: Benn urges caution on Bosnian air strikes - Minister fends off attacks from both sides - Labour says dam 'sullied' aid programme

Tony Benn, the veteran left- winger, joined senior Tory MPs yesterday in urging great caution over launching air strikes against Bosnian Serbs in response to the Sarajevo market massacre.

Involving Britain in a Balkan war, the outcome of which could not be foreseen, raised political as well as military questions, Mr Benn told the Commons. More immediately, British troops could be endangered and humanitarian aid halted.

'Were the Government to be cautious on this matter, there would be far greater support than might be apparent from some of the comments in the House,' the MP for Chesterfield said, to a rumble of approval.

Arguments for and against air strikes were pressed on the Government after Alastair Goodlad, Minister of State at the Foreign Office, answered an emergency question put down by Labour in the wake of the weekend carnage. With Douglas Hurd, the Foreign Secretary, attending a European Union council meeting and Nato defence ministers due to meet tomorrow to consider air strikes, Mr Goodlad conducted a holding operation.

Condemning 'this brutal and senseless act', he said action over Sarajevo could not await an overall negotiated settlement on Bosnia. 'It is essential that the UN and Nato should consider immediately practical means for halting the bombardment of civilians there.' Echoing John Major's words, Mr Goodlad told MPs: 'We're looking for effective action, if necessary muscular action, to protect the civilian population of Sarajevo.'

But Jack Cunningham, Labour's foreign affairs spokesman, said recent history showed that Western policy was in disarray over the problems of former Yugoslavia. 'The record is one of failure to prevent atrocities resulting in the wanton slaughter which shocked the world this weekend.'

He called on the Government to press immediately for the reopening of Tuzla airport and the lifting of the siege at Sarajevo. If the Serbs and Croats did not accept these decisions they should be 'enforced by the use of the vastly superior airpower of Nato'.

Mr Goodlad said Unprofor command with Nato support must apply the pressure necessary to halt the attacks. 'If the military commanders advise this requires tactical air support, we shall back their judgement.'

Military commanders had consistently advised that air strikes would not end the war and could hamper humanitarian relief, the minister said. 'But in specific situations the tactical use of air power can help achieve defined objectives . . . We await the assessment of military commanders, but are fully prepared to see air power used if it will improve the situation.'

Patrick Cormack, Conservative MP for Staffordshire South and a persistent advocate of tougher action, wanted the Serbs to be given an ultimatum, backed by the threat of real force, to lift the siege of Sarajevo and to remove the heavy weapons from the hills around the city. 'Vacillation and indecision has gone on for too long.'

But a succession of senior Tories were concerned at the consequences of air strikes for the aid workers and British troops. Sir Nicholas Bonsor, chairman of the defence select committee, said it would be wrong to change policy because of the latest 'appalling' tragedy. If there were a change, troops and aid workers should be in a 'place of safety before we embark on an act of aggression which will take us into this conflict as a participant'.

Michael Jopling, a former Conservative Cabinet minister, pointed out that the experience of air strikes in Vietnam and the Gulf was that they were not able to remove military targets on the ground. And troops could move at night.

Mr Benn underscored the warning, the force of which was acknowledged by Mr Goodlad.

Cries of 'shame' and 'racist' greeted a swipe by Andrew Faulds, Labour MP for Warley East, at Mr Hurd and Malcolm Rifkind. The fiercely pro-Arab Mr Faulds said: 'There is considerable dismay at Britain's craven conduct in these matters - the leader of 'Don't let's do anything' - under a Christian Foreign Secretary and a Jewish Minister of Defence.'

The normally lugubrious Mr Goodlad quickened just once during the exchanges, when Sir Russell Johnston, for the Liberal Democrats, said military action would be much more hazardous now than when his party advocated it to break the seige of Osijek. Action had to be taken to defend Sarajevo, Mostar and Tuzla. Mr Goodlad said it was 'irresponsible' of Sir Russell to 'play politics' with the situation in Bosnia. 'If the half- baked, half-measures advocated by the Liberal Democrats had been adopted, we would have been no nearer a solution, but UN troops would very likely have become participants in the conflict. The ex post facto wisdom of Paddy Ashdown is preposterous.'

Britain's pounds 234m aid to the controversial Pergau dam in Malaysia was raised at Question Time, drawing an assurance from Mark Lennox-Boyd, Under-Secretary of State for Overseas Development, that the aid programme 'is not and will not be linked to arms sales'. The minister, perhaps, was using his tenses with care.

The Labour spokesman, Tom Clarke, said the reputation of Britain's bilateral aid programme had been 'sullied' by the decision to fund the dam. In defiance of warnings by civil servants and ODA ministers against improper use of aid, ' pounds 234m of British taxpayers' money is being wasted on Pergau for the sole purpose of boosting the arms trade'.

Mr Lennox-Boyd steered clear of the specifics of Pergau, saying it was a matter to be discussed by the foreign affairs committee. 'British aid has contributed to Malaysia's rapid economic development and to the productive relationship which we have with Malaysia in many fields of activity, including trade,' he said.

Trade with Malaysia was three times its 1988 level - the year when Pergau was reportedly linked with a pounds 1.3bn arms deal pushed by Margaret Thatcher.