By Stephen Mulvey BBC News Online

If this was an election in another country, President Vladimir Putin could justifiably tell his opponents: "It's the economy, stupid."

It's the health of the Russian economy which underpins Mr Putin's massive 80% approval rating.

While the economy is buoyant, so is Mr Putin

But since this is Russia in 2004, Mr Putin has no-one to address these words to - he has no real opponent and little need to bother himself with a campaign.

The country's economic surge, since the crash of 1998, has coincided with a political freeze - the media has been tamed, opposition parties marginalised, and civil society put on hold.

Last year, the US-based organisation Freedom House judged that the Russian media was no longer free, and after December's parliamentary election it said the country was no longer an "electoral democracy".

"For Russia, 2003 was marked by further movement toward authoritarianism by President Vladimir Putin and the government," its latest report says.

"A ruling elite dominated by former military and security service officers now [occupies] 25% of key government and legislative positions," it adds.

Unease over Chechnya

There are a number of reasons for the strength of the Russian economy, the chief one being the high price of oil and gas, the country's main exports.

REASONS FOR PUTIN'S POPULARITY His real successes and achievements: 22% Hopes that he will succeed in doing something in future: 32% His personal and professional qualities: 22% It's just that no-one better is visible: 21% Difficulty answering: 4% Source: VTsIOM opinion poll, January 2004

Rapid growth has also been easier to achieve because of the depths to which the economy sank in the Soviet and post-Soviet crisis years.

The 75% devaluation of the rouble in 1998 itself gave domestic producers a big boost.

But on top of that, Mr Putin has established a degree of order that was not there before he took over the reins at the end of 1999.

Salaries and pensions are now largely paid on time. Taxes are collected - thanks partly to ambitious and successful tax reform. The bureaucracy has been streamlined. Some state monopolies are being broken up.

While some of the most flamboyant oligarchs have been jailed or obliged to leave the country, others have been left to get on with their business in an improved climate.

But curiously, while Russians enjoy their rising living standards and give Mr Putin their backing, only a minority think he is "handling Russia's problems successfully".

Polls also show that there is widespread unease about his policy towards Chechnya. Much has changed since Mr Putin was first elected four years ago, when his popularity was founded on the decision to send troops back into the breakaway region.

No military reform

Mr Putin's pro-Western foreign policy since 11 September has also not been hugely popular, especially with his allies in the military and the security forces.

There are serious unsolved social problems too, including Russia's rapidly shrinking population, an increase in drug abuse and a gathering Aids crisis.

Analysts also debate how far Mr Putin has succeeded in restoring central control over Russia's regions. He has appointed his own governors in a handful of super-regions, but how much real power they give him over the far-flung provinces is unclear.

The precise nature of Mr Putin's relationship with the military and security forces - the siloviki - is also obscure.

He has failed, despite repeated pledges, to carry out any serious reform of the armed services.

And there have also been moments - such as the arrest of the Yukos oil oligarch Mikhail Khodorkovsky last summer - when correspondents have begun to wonder whether the siloviki, not Mr Putin, might actually be in control.

Going into this election, Mr Putin looks impregnable, but his strength is founded on his popularity, which in turn is founded on Russia's economic success.