Jan Cienski in Warsaw -

Donald Tusk, the Polish prime minister, is facing a slowing economy, dissent from within his Civic Platform party and fraying ties with his European partners over the next EU budget - but he is still a very lucky man because of the calibre of the opposition he faces at home.

That is because the right-wing Law and Justice party (PiS) has been captured by a lunatic bloc dedicated to the proposition that the April 2010 air disaster which killed president Lech Kaczynski and 95 others, many of them senior officials, at Smolensk, Russia, was a nefarious plot and not an accident. This has acted to spook centrist voters and defang the opposition, led by the dead president's twin brother Jaroslaw Kaczynski, as a credible alternative to Civic Platform - something that is proving to be off immense help to the government as the economy reacts to the Eurozone crisis.

The air crash returned as a major topic in late October when Rzeczpospolita, the country's leading business paper - complete with a salmon-coloured economics section - published a blockbuster revelation on its front page, that traces of nitroglycerin and TNT had been found on the wreck of the Polish government airliner.

Hours after the paper had hit the stands, Kaczynski and his lieutenants, surrounded by grieving families of those killed in the air crash, were touting this as proof that the crash was "murder" - and not simply a tragic accident. "Murdering 96 people, including then president of the republic and other exceptional public officials is an incredible crime and anyone, even through fraud or partisanship who has the slightest thing to do with this will have to bear the consequences," Kaczynski declared, before calling on Tusk's government to be dismissed.

The comments marked a break with Kaczynski's long-standing policy of skating on the edge of saying what he had really thought had happened two years ago in Smolensk, leaving the strongest allegations to his supporters. Some of them accused Russia's Vladimir Putin of being behind the crash (sometimes with allegations that Tusk was also involved), and the speculations of what brought the plane down have ranged from a Russian missile to Russian kill squads who murdered the survivors, to machines which pumped helium into the air, changing its density and crashing the airliner.

Both Polish and Russian government investigations found that the cause of the crash was that undertrained Polish pilots tried to land the airliner in a dense fog. No traces of bomb damage have been found on the wreckage.

The Rzeczpospolita story allowed Kaczynski to say what he really thought. Unfortunately for him, the prosecutor's office called a news conference just after his and denied the whole story and the paper also followed with a retraction of its story - both the editor in chief and the reporter responsible have since been fired. The end result has been to destroy Kaczynski's recent attempt to migrate towards the political centre.

The centre ground

Kaczynski had held a series of well-publicised conferences including one with some of the country's leading economists, where he sat and quietly listened to a serious discussion of the country's economic situation and of his party's programme. He also named a technocratic professor as a candidate for prime minister in case his party succeeded in unseating Tusk, seeking to calm voters worried about Kaczynski again being premier (he was in charge of the government in 2005-2007).

The shift to the centre saw immediate results; his Law and Justice started to steadily gain in opinion polls. In early October, it had the support of 39% of those polled while Civic Platform had only 33%, the first time in many years that Kaczynski's party led.

As a result Tusk rushed to relaunch his government, spelling out a new economic programme and admitting in television interviews that he had been forced to act by Kaczynski's resurgence. His party also appeared to be fracturing between its liberal and conservative wings over controversial issues like abortion and refunding in-vitro fertilisation.

But Kaczynski's fiery declaration of the crash being murder again put off voters. A new survey finds that Tusk's party is back on top with the support of 42% of those polled while PiS was at 30%. Pawel Wronski, a columnist for the Gazeta Wyborcza newspaper, wrote: "The president of PiS has blown up like a grenade... The carefully constructed image built since the spring by PiS PR specialists of Jaroslaw Kaczynski, who with a genial smile listens to specialists debate about the future of Poland, has been blown to smithereens."

Tusk's lucky streak looks set to continue, with Law and Justice party spokesman Adam Hoffman proclaiming that the party will "continue occupying itself with Smolensk despite the fall in opinion polls."

Leszek Miller, a former premier for the ex-communist Democratic Left Alliance, wryly notes that he has the impression that Tusk really needs Kaczynski. "He reminds what could happen to Poland if Kaczynski gains power."