A ROAD MAP to the by-ways and culs-de-sac of Russia's power struggle costs only 10 roubles, just over 1p, in the basement canteen of the Great Kremlin Palace. It is a copy of Russia's constitution, stacked on a shelf along with a biography of Richard Nixon (very popular, says the sales lady) a book on Boris Yeltsin (very unpopular) and a Russian translation of KGB: The Inside Story by Oleg Gordievsky and Christopher Andrew (heavily browsed but too expensive at 540 roubles).

The constitution - or rather how it should be interpreted - lies at the heart of the vicious power struggle raging upstairs in the main hall, where the Congress of People's Deputies gathered yesterday for a second day of attacks on the authority of President Boris Yeltsin.

The problem for Russia's booksellers, and its politicians, is that the constitution has a very short shelf-life: it keeps changing. The version now on sale in the basement arrived only yesterday morning, freshly printed to include the latest revisions to a document first drawn up on orders from Leonid Brezhnev in 1978.

For a decade the constitution, like the system it anchored, resisted all change. Then, with Mikhail Gorbachev in the Kremlin, it began to fall apart. The first big change was in 1989, followed by an avalanche of additions and excisions as the Soviet Union hurtled towards oblivion. It was revised three times in 1990, twice in 1991 and then, during two sessions of the Congress of People's Deputies last year, three more times. In all, dozens of articles and clauses have been chopped and changed, leaving 89 pages (plus assorted annexes) of utter confusion.

And it is in this constitutional swamp left over from Communism that President Yeltsin and the Congress of People's Deputies, led by its chairman, Ruslan Khasbulatov, are now waging a struggle for power that, both sides have warned, could send Russia the way of the Soviet Union.

Article 3 would seem to leave little room for argument. Russia, it says, is ruled according to the 'principles of a division of power between the legislative, executive and judicial branches'. But how should this power be divided? Mr Khasbulatov and many of the more than 1,000 Congress deputies who support him point to Article 104. It defines Congess as the 'supreme organ of state power'. Mr Yeltsin and his allies prefer Article 121. It describes the presidency as the 'supreme post'.

The same contradictions existed in the Soviet Union too. But then they were easily resolved. The Soviet legislature was no more than a rubber stamp for decisions taken by the Politburo of the Communist Party. With the party gone, only a void remains.

The muddle was to have been resolved with a referendum to fix once and for all where ultimate power should lie. In December, when the constitutional issue first erupted with full force, Mr Yeltsin and Mr Khasbulatov endorsed a compromise package calling for a popular vote in April. But the deal, described by Mr Khasbulatov yesterday as 'the work of the Devil' is now off and with it any hope of a clear-cut answer to the question, sharpened by bitter personal rivalries, of how power should be shared.

Instead of addressing the issue head-on with a referendum, the Congress yesterday chose to chip away further at Mr Yeltsin's powers, restricting his right to appoint four key ministers and leaving the Central Bank under parliamentary control. 'The situation is very nasty,' said Leonid Volkov, a radical ally of Mr Yeltsin. 'The constitution is the legacy of a totalitarian regime. It was never voted on by the people. It was worked out by and for the party. There have been changes but it is still based on Communist power which does not exist anymore, on KGB terror that does not exist either.'

Many conservative legislators also want the mess resolved. Alexander Kobsikov, elected to represent a state farm, insists that only the Congress, and a smaller standing parliament, the Supreme Soviet, can guarantee real democracy and open debate.

(Photograph omitted)