With no immediate end in sight to the war with Belgrade, the problems facing Tony Blair over the conflict are set to increase.

Until now, the prime minister has won overwhelming support from his own backbenchers as well as members of the public for the action.

There have been opponents, most notably from left-wingers like Tony Benn, Tam Dalyell and Alice Mahon and the prime minister has frankly expressed his dismay at their stand on the war.

He recently told them during question time that he just could not understand their position. This is clearly true.

For Mr Blair the war, as he announced himself, has now become a moral one as the Nato forces attempt to stop the killing and the ethnic cleansing in Kosovo and try to provide food and shelter for the apparently never-ending flood of refugees.

In fact, the war aims have been subtly amended over the weeks since the conflict began. It has patently failed in its original aim of averting a massive humanitarian disaster.

Mr Benn voiced immediate opposition to the Nato strikes

Now, the military is attempting to deal with that catastrophe on the one hand, while trying to bomb Slobodan Milosevic into submission with the other.

Any sign that the Yugoslavian leader is cracking under the pressure is seized on by the politicians to claim the escalating number of air strikes are working.

But there is no suggestion that this conflict is anywhere near a final resolution and every week longer it continues, so the political pressure will intensify on Tony Blair.

The cost factor

For one thing, wars cost vast amounts of money and Chancellor Gordon Brown - while currently meeting the cost from the contingency reserve - may soon start worrying that he will be left with little room to manoeuvre in the lead up to the 2001 election.

Victims of what Mr Blair calls a 'moral war'

And heaven forbid that the military action drags on so long that the cost starts eating into plans to push money into health and education.

Secondly, there is the pressing problem about ground troops.

Mr Blair has time and again insisted that there are no plans to send troops into a ground war that would inevitably lead to British casualties.

But many experts claim, without them, the war will not succeed.

Nato General Secretary Javier Solana has stressed that, while there are no plans for such action, anything must be kept open as a future option.

The prime minister was recently told in the Commons by independent MP and former BBC war correspondent Martin Bell that ground troops were essential.

"If the political will is not there, let us admit it is not there and hang our heads and walk away in shame," he said.

But, even if the prime minister does succeed in avoiding that option - and the pressure on him to back a ground war is increasing by the day - he is still committed to sending in troops to ensure Kosovo's safety once the war has been brought to a successful conclusion.

Martin Bell believes ground troops must be sent

And that carries its own risk of casualties if elements of the Yugoslav army continue to skirmish with the Kosovo Liberation Army.

The public have made it clear that they do not want to see British lives lost in the war. What effect such casualties would have on the politicians and public support is hard to imagine.

It could lead to immediate demands for withdrawal or, as history might suggest, lead to more robust calls from voters for a hammer blow to finish off Milosevic.

Opposition support

Meanwhile, the Tories have maintained their guarded support for the action but William Hague has also quizzed the prime minister on exactly where he believes the conflict is heading.

It is difficult to see the Tories abandoning their support for the government, but Mr Hague is equally not about to give ministers a totally uncritical hearing.

11 April: 2,000 protest in London against the Nato strikes

He has a group on his own side who are just as critical of the war as Labour's opponents.

As all this is continuing, of course, Labour is heading into a giant mid-term electoral test with local council, Welsh assembly, Scottish Parliament and European Parliament polls looming over the next couple of months.

He has insisted the conflict is a totally separate issue to the elections but in all the polls voters are certain to have the conflict as one of their major concerns.

At the moment, it is likely that would have the effect of increasing support for the government and boosting Mr Blair's popularity.