By Paul Reynolds BBC News Online world affairs correspondent

The latest reports to be delivered to the Council on Friday by the two senior weapons inspectors - Hans Blix and Mohamed ElBaradei - are likely to contain plusses and minuses.

UN inspectors have now been allowed to speak to Iraqi scientists in private

The minuses will enable the United States and Britain to argue that Iraq has failed to co-operate and the plusses will let France, Germany and Russia contend that there need to be more inspectors and more time.

Such ambiguities could then lead to a crisis within the Council if the US and UK move to introduce a resolution authorising force and others resist.

If there is no agreement on that resolution, Washington, probably supported by London, will go to war anyway.

Such a decision would throw the whole UN system into doubt.

European discord

In advance of the inspectors' reports, France is sticking to its "no war for now" stance and is pressing proposals for the containment of Iraq by increased inspections.

From the Iraqi perspective, he will be too demanding. From the perspective of the Bush administration, he will be too judicious. From the perspective of people who want peace at any cost, he will be too uncompromising John Rich Former US diplomat

Hans Blix profile

Russia is on board with the French and is threatening to use its veto "if necessary", in President Putin's rather unclear words.

The German Chancellor Gerhard Schroeder says: "We can disarm Iraq without war."

But the UK Prime Minister Tony Blair is holding firm with President George W Bush and has written to his fellow European Union leaders, who are holding an emergency summit on Monday.

On the use of force he said: "We must make it clear that no member state rules it out."

And of the French move, the UK Foreign Secretary Jack Straw says it is "unrealistic and impractical". It shows, he states, that "defiance pays".

All sides, of course, are saying that war is only a last resort. They always do.

Some progress

On the plus side in the reports, Mr ElBaradei, the nuclear inspector, may repeat the "cautious optimism" he expressed over Iraq's attitude during a visit by himself and Mr Blix last weekend.

Mr Blix will be able to report progress on interviewing Iraqi scientists in private, and on surveillance flights by U-2 aircraft.

AL-SAMOUD II

Tactical surface-to-surface ballistic missile powered by liquid fuel Tested at range of 183 km - in excess of UN 150-km limit Diameter also in excess of prescribed limit May be able to deliver biological or chemical warhead

On the minus side, a new issue has come to a head - whether Iraq is in breach of the original Gulf War ceasefire resolution 687 which prohibited it from acquiring or developing rockets with a range beyond 150 kilometres (90 miles).

Mr Blix raised this problem in his last report to the Council on 27 January when he said that test firings of two rockets - al-Samoud 2 and al-Fatah - had reached 183 km and 161 km respectively, which he described as "significant".

The diameter of the al-Samoud missile had also been increased despite an earlier UN order, he said, and 380 rocket engines had been illegally imported.

Since then, an international panel has examined the question and its findings will be given to the Council. If they confirm the violation, then the US and Britain will have their hand strengthened.

But countries calling for a delay might argue that the violation is relatively small and that the missile programme has been stopped anyway.

Material questions

Another key issue remains in the minus column - a full accounting for the so-called "missing" chemical and biological warfare material has still not been made.

This includes the VX nerve agent, anthrax production and special munitions. Iraq says the material was never made or was destroyed. The UN wants more evidence.

Mr ElBaradei is also expected to deal with another contentious issue - the attempted import by Iraq of thousands of aluminium tubes.

In his last report he implied that he believed Iraq's claim that these were for the manufacture of rockets but the Americans still think they might have been intended to enrich uranium.

Assessments crucial

As can be seen, the arguments can get very technical and detailed.

What matters is the general assessment made by governments.

The US and UK see failure - a pattern of lack of co-operation amounting to a breach of resolution 1441. For them, concessions do not amount to compliance.

Others see hope - and a way of containing Iraq indefinitely without the need for force. For them, concessions by Iraq are an encouragement to continue.