By Paul Reynolds BBC News Online world affairs correspondent

The Iraqi declaration on weapons will be subject to detailed tests against intelligence information and by on the ground inspections.

However it should not be an immediate trigger for war even if Baghdad does not declare the weapons of mass destruction which the United States and Britain says it has.

Iraq has lied before and is lying now Ari Fleischer, White House spokesman

The National Security Council in Washington is expected to send the declaration to the various agencies which have the expertise to examine it - especially the CIA and the Defence Department.

In London, Foreign Secretary Jack Straw said: "Even if Saddam makes the mistake of lying once again, we will want to nail his lies."

He said that "robust inspections and hard questions" would help test the truth of the declaration.

Thirty more inspectors are being sent to Iraq this weekend to add to the 17 there already.

Mr Straw called the declaration a "career choice" for Saddam Hussein.

Of course if significant lies are established, then Iraq might be found by the United States at least to be in material breach of UN Security Council Resolution 1441, in which case war could follow.

In advance of the Iraqi document, Washington is keeping up the pressure.

"Iraq has lied before and is lying now," said the White House spokesman Ari Fleischer.

The US has already accused Saddam Hussein of lying

President Bush's National Security Adviser Condoleezza Rice has urged Dr Hans Blix, the head of the UN weapons inspection organisation Unmovic, to get Iraqi scientists out of the country to question them away from the influence of Saddam Hussein's security agents.

This is allowed for in the Security Council resolution.

Only in that way, it is believed by some experts, will the real extent of any weapons programmes be uncovered.

Iraq has indicated that its declaration will be thousands of pages long.

This is partly because it has to declare not just any weapons of mass destruction - which it says it does not have - but also details of its ballistic missile development, its efforts to build unmanned aerial vehicles and other chemical dispersal systems.

It also has to disclose all of its civilian chemical, biological and nuclear programmes.

According to US intelligence, Iraq possesses:

• 360 tonnes of chemical warfare agents, including 1.5 tonnes of VX nerve agent;
  

• 3,000 tonnes of chemical precursors (which are developed into chemical weapons) including 300 tonnes uniquely used for VX;
  

• Growth media for 20,000 litres of biological warfare agents. Any Iraqi claims that this will have degenerated will not be accepted as mustard gas found in shells in 1997 was active;
  

• Shells for use in biological warfare - 20,000 are missing say the British, 15,000 say the Americans;
  

• 6,000 chemical warfare bombs.
  

Other key concerns include the following:

Nuclear

• Why did Iraq try to import 60,000 aluminium tubes? Rapidly spinning rotor tubes in centrifuges are used to separate weapons grade uranium, though both the British and American reports acknowledge that the tubes could be used for conventional weapons as well.
  

• Why did it try to import other equipment, including vacuum pumps, a winding machine and special chemicals needed in gas centrifuge cascades?
  

• Did it, as the British dossier alleges, try to buy uranium from a country in Africa?
  

• Where is the information, said by the CIA to be missing, on details of its nuclear programmes such as procurement logs, technical and experimental data, and weapons design?
  

Chemical

• What is going on in the important chemical production centres at Tarmiyah (a research centre), al-Qa'qa (phosgene production) and al-Sharqat (a complex in the north west desert)? These have been newly built or rebuilt.
  

• Is Iraq, as the CIA alleges, trying to hide the real purpose of the Fallujah ll chemical plant which makes chlorine and phenol? Both chemicals have civilian uses but both are also precursors for blister and nerve agents.
  

Biological

According to the British dossier, "facilities of concern" which should be explained include:

• The castor oil production plant at Fallujah lll. Castor oil is used for brake fluid but also for the biological agent ricin;
  

• The al-Dawrah foot and mouth vaccine plant said to have been used for biological agent research;
  

• The Amariyah vaccine plant at Abu Ghraib, a previous centre of biological agent research and now expanded;
  

• The CIA is particularly interested in Iraqi development of mobile biological laboratories which could be hidden from inspectors.
  

Missiles

• Has Iraq retained any Scud missiles from the Gulf War? It should not have.
  

• Is it trying to develop rockets with ranges above the 150km limit imposed by the UN? If not, why has it built a new rocket test bed at al-Rafah, and rocket fuel and production facilities at al-Mutasin and al-Mamoun?
  

Delivery systems

• Has it tried to make the Czech-made fighter the L-29 into an unmanned plane which could be used to spray chemicals?
  

• Does it have any drop tanks or helicopter sprayers for use in chemical warfare?
  

• What happened to Scud warheads which might have been filled with VX agent?
  

The list of questions is long.

The British Government says that time will have to be taken to study Iraq's declaration.

Junior Foreign Office Minister Bill Rammell, who has just returned to London after consultations at the UN in New York, said: "We should not rush to judgment."

In other words, it will have to be tested in the field.

He said that Dr Hans Blix, head of the inspection organisation Unmovic, would probably give a preliminary assessment to the UN Security Council next week.