By Russian affairs specialist Malcolm Haslett

Russia's prime minister and acting president, Vladimir Putin, has been formally nominated as a candidate for the presidential election.

But, with speculation that the Chechen war is not going so well, Mr Putin's popularity could suffer, thus opening up the presidential race to other candidates.

Mr Putin was nominated as a presidential candidate by an impressive group of almost 200 personalities from the political, business and cultural worlds.

The politicians come from a number of different groups. They include the President of Tatarstan, Mintemir Shaimiyev from the All Russia group, Governor of Saratov Dmitri Ayatskov from the old pro-Kremlin "Our Home is Russia" (NDR) party and Governor of Kursk Alexander Rutskoy, who has signed up for the recently formed "Unity" bloc.

Another name is that of former deputy premier Anatoli Chubais, a leading light in the Union of Forces of the Right (SPS) and also chairman of the Electricity company UES.

The head of the gas giant Gazprom, Rem Vyakhirev, is also on the list - as are opera singer Yelena Obraztsova and pop artist Mikhail Boyarsky.

This formidable array of personalities suggests a wide support in society, and that impression is certainly supported by current opinion polls.

One survey, by the ARPI organisation, suggests that 62% of Russians would vote for Mr Putin if an election was held now, enough to give him a clear overall majority and immediate victory, without a run-off.

Another organisation, VtsIOM, suggests that 56% of Russians would vote for the acting president.

Opposition politicians have argued that there has been an element of doctoring of recent opinion polls, to boost support for Mr Putin.

But they also said that before the Duma election last month, the result of which was predicted by the opinion polls fairly accurately.

Chechnya factor

Some analysts are warning, however that - now that the Russian forces have begun to meet stiff opposition around the Chechen capital, Grozny - all this could change very rapidly.

The English-language Moscow Times, for instance, talked this week of the 'unravelling' of Putin's victory.

It compares Russia's Chechen offensive to the ill-fated Tet offensive launched by US forces in Vietnam in 1968, which most experts agree demonstrated that the Vietnam war was 'unwinnable'.

And in Izvestia, columnist Andrey Stepanov analyses some of the more detailed findings of opinion polls, pointing out that while most Russian feel generally positive about the Chechen campaign, they do not agree on what its aim is.

He also points out that 17% of Russians say they know what is in the economic programme of the pro-Putin "Unity" bloc - even though it doesn't have one!

Mr Stepanov warns that the high, but ill-defined expectations of Russian voters, could very quickly turn to disillusionment and hostility against Mr Putin if they are not satisfied.

Media support

These are serious rejoinders, but Mr Putin retains tremendous advantages over his rivals.

He can depend for support on a large part of the national media, as the Duma campaign showed, and he has also been helped by the weakness of his main rivals.

The Communists polled well in the Duma vote, but most people think that with the colourless Gennadi Zyuganov as their candidate again, they have little chance of winning an overall majority of votes.

Ex-premier Primakov has suffered from the divisions within the Fatherland-All Russia bloc, and seems unlikely to stand.

And liberal anti-war candidate Grigori Yavlinsky is seen as having little chance.

But Mr Putin's strength is not just as a 'war' candidate. Many Russians back him as a 'strong leader' candidate, which depends partly on how the war goes, but not entirely.

He is popular because he gives the impression of someone who will "get things done", and that is what Russians feel they need in a president, above all.

A military disaster could still de-rail Vladimir Putin's express train to the presidency - but it will have to be a pretty big disaster