If there is one thing worse than having to share a cake with a gluttonous ogre, it is having to share a cake with two gluttonous ogres. That is the predicament that French clubs are agitating to avoid as hyper-rich Monaco get ready to join Paris Saint-German in Ligue 1, potentially leaving the others to squabble over crumbs.

Monaco are top of Ligue 2 and could secure promotion this weekend with a win against fourth-placed Caen, who, as it happens, are the last team to have beaten Claudio Ranieri's side, 17 matches ago.

Even if Caen repeat that feat, Monaco are still likely to do enough over the three games after that to go up – and begin looking down on everyone but PSG thanks to the largesse of their billionaire Russian owner, Dmitry Rybolovlev. The prospect of France's two automatic Champions League places being annexed by PSG and Monaco for the foreseeable future has led to other clubs taking radical action.

Rybolovlev took a 66% stake in the erstwhile principality-owned club around Christmas 2011, when Monaco, six months after being relegated from the top flight for the first time in 34 years, were bottom of Ligue 2 and in real danger of dropping to the third tier. He immediately bankrolled the recruitment of nine new players, including setting a Ligue 2 transfer record by paying €7.5m (£6.3m) for the Moroccan winger Nabil Dirar. Monaco soared up the table and eventually finished eighth.

Last summer they invested heavily again, signing internationals such as Denmark's Jakob Poulsen and Sweden's Emir Bajrami before breaking the transfer record again by splurging €11m on the River Plate midfielder Lucas Ocampos.

Monaco won their first match of this season 4-0 against Tours and have seemed certainties for promotion ever since, although their domination of the league has not been as total as their financial superiority, which is one of the reasons why Ranieri is expected to leave this summer, with Roberto Mancini and José Mourinho among the names most often cited as potential replacements.

Once their ascent to Ligue 1 has been confirmed, Monaco can start recruiting on another level, rivalling PSG and anyone else for the world's best players. Their first aim is believed to be getting back a couple of top France-based players whom they had to sell after relegation, buying back the central defender Nicolas N'Koulou from Marseille and the goalkeeper Stéphane Ruffier from Saint Etienne. After that, according to reports, they will turn their attention to Radamel Falcao, Carlos Tevez, Wayne Rooney, Edinson Cavani, and so on and so on.

You get the picture: money is no obstacle. But hostility from other French clubs is. Because in late March they united to threaten to ban Monaco unless the club agreed to move towards greater financial equality – Rybolovlev may not be prepared to put in quite as much cash as PSG's Qatari owners have already done, but he does not need to because he has an advantage that no one else enjoys: Monaco's status as a tax haven. And that is what the other clubs have set out to abolish.

Monaco has always benefited from the principality's special status. The club pays far less corporation tax than its French counterparts and although an agreement means any French player whom the club employs must pay tax in France (though they can still benefit from a 20% reduction on national insurance), foreign players get to keep all of their earnings.

By way of comparison, where PSG reportedly have to fork out in the region of €30m per year to Zlatan Ibrahimovic, Monaco could give the Swede the same take-home salary for an outlay of just €9m.

This special status has long irritated other clubs, but the power of Rybolovlev at a time when others are facing cost cuts and tax hikes has convinced them to finally do something about it. The Ligue de Football Professionnel has voted unanimously to introduce a new rule stipulating that, as of 2014, all clubs must be registered with France's fiscal authorities.

That was a declaration of war on Monaco's privileges and the club from the principality is outraged, with its vice-president, Jean-Louis Campora, complaining about rivals "holding a gun to our head … [to make us] reject our identity," adding ominously that "the owner has a plan for the club and for French football but if it's decided that Monaco are not wanted any more, then everything stops".

As positions became more entrenched, the French Football Federation has stepped in to mediate, perhaps alarmed by rumours that Monaco are planning to turn their back on Ligue 1 and apply to join Serie A instead. Those rumours have been rubbished by Campora, but they do get to the core of the pickle: how can French football welcome Rybololev's wealth without the competition being made poorer?

The FFF says an "appropriate legal framework" will be found "to safeguard the interests of French football". Compromises suggested in the media include admitting Monaco but not letting them share the television revenue, or forcing them to play a quota of homegrown players. Others argue that, even if Rybolovlev is not scared off, such contrivances are a recipe for mediocrity and that rather than try to shackle Monaco, the league should encourage them to sign as many world-class players as possible, because attendances, standards and France's Uefa coefficient will all rise as a result.

"It's true that Monaco have an advantage in the transfer market, but that can only be beneficial for French football," the Bordeaux midfielder Ludovic Obraniak told French radio station RMC. "To have two big teams, PSG and Monaco, going head to head at home and representing you in Europe will attract interest and investors. Otherwise, with the recession and the new taxes, French football will die. And if Falcao or someone signs for Monaco tomorrow, and we already have Ibrahimovic at PSG, what a joy it would be to play against such players. Not everyone gets to face such stars in their career, so I view that prospect positively rather than with jealousy."