The predicted victory of the Polish opposition in Sunday’s general election would be a massive boost for the European Union and a body blow to radical right-wing populism across the continent.

Former premier Donald Tusk, leader of the centre-right Civic Coalition, gave a masterclass on how to defeat populists on their own terms, even if it wasn’t always pretty to watch.  In particular, Tusk outmuscled the ruling Law and Justice (PiS) party on migration, attacking the government for being too lax, and then capitalising on a corruption scandal involving visas within the foreign ministry.

It proves once again that creating a number of different opposition coalitions may be the best tactic to dislodge a dominant radical right-wing government, as it enables parties to mount a range of attacks from different directions, without trying to find a muddled consensus, a weakness that doomed the Hungarian opposition in the election there last year.

If the result is borne out by the final results, expected on October 16, Poland could finally take its rightful place at the centre of Europe. Poland is the fifth largest country by population and the sixth by gross domestic product. It also has a key geopolitical role as the most important EU state facing Russia and bordering Ukraine – of which it has been a vital supporter, in terms of harbouring refugees, providing military aid and in stiffening the backbone of wobblier Western European allies.

Poland is the biggest of the former communist states (at least until Ukraine joins) in Central and Eastern Europe and regards itself as their natural spokesman through the Visegrad Group (V4) of Central European states, even if the others do not always quite see it that way. The Law and Justice government has also tried to expand this role through the Three Seas Initiative, covering most of Central and Southeastern Europe, though this has so far fallen far short of its early ambitions.

But under Law and Justice’s eight-year rule, Poland squandered its key geopolitical position and the boost to it that Russia’s invasion of Ukraine should have brought.

PiS engaged in a long fight with Brussels over its blatant violations of the EU’s values, notably on the rule of law, as it attempted to consolidate its control of the state. It pursued an obstructive policy in the European Council, together with Viktor Orban’s Hungary. This has hampered the EU’s attempts to prepare the bloc to meet the challenges of climate change and growing refugee flows, as well as the reforms and funding needed to cope with a greatly enlarged union in the future.

Purely for electoral advantage PiS also provoked rows with Germany and even Ukraine as a way of stealing votes from the far-right Konfederacja party.

Tusk, as a former head of the European Council, could now be ideally placed to rebuild Poland’s relations with Berlin, Kyiv and Brussels, and achieve the prize the country has sought since EU accession two decades ago: a place at the heart of European decision-making.

However, it won’t all be plain sailing. Any Polish government is likely to disagree with Brussels on the pace of how the bloc approaches green issues designed to tackle climate change and make future growth more sustainable.

Poland, with a big farming sector and as a large recipient of EU structural funds, will also inevitably want to preserve its interests when Ukraine enters proper negotiations to join the bloc, as it will be a natural competitor for both aid and exports.

Any Polish government will also continue to fight against quotas for accepting refugees, and will be suspicious of greater majority voting in the European Council.

Yet a Tusk-led Poland would have no interest in provoking fights with Brussels for the sake of it, unlike Orban’s Hungary, and this unholy alliance would likely cease. Slovakia’s returning populist leftist premier Robert Fico would also see how the wind is blowing and would likely now look north to Poland rather than south to Hungary.

All this would change the mood music in Europe and make Orban even more isolated. It could also mean that the Hungarian strongman becomes more vulnerable to determined EU pressure to preserve what remains of Hungary's democracy – and ideally repair the damage –  because he would lack the threat of a potential Polish veto to back him up.

If the exit polls are correct, and populism is pushed back in Central Europe – where it broke through first and remains strongest – let’s hope the EU knows how to take advantage of this before we get another populist wave – this time perhaps in Western Europe.

This blog first appeared on bne IntelliNews's Editor's Picks. To sign up for the daily Editor's Picks newsletter, please click here.