Donald Tusk, the European Council president, has warned that Poland could soon follow Britain out of the European Union.
The 60-year-old, who served as Polish prime minister between 2007 and 2014, suggested his country's ruling party are looking to emulate Britain's example and leave the soon-to-be 27 country bloc at the earliest opportunity.
Tusk said the populist right-wing Law and Justice party (PiS), Poland's majority party, was planning a Brexit-style referendum by the end of the decade.
"I have no doubt that for PiS one of the goals is to 'free' Polish politics from the burden of the EU," Tusk told Tygodnik Powszecnhy magazine, as reported by The Times.
A centrist and pro-European PM during his spell in charge, Tusk is planning to re-enter his country's political arena in 2020. He warned PiS was deliberately "creating a conflict with the EU as it limits the omnipotence of the ruling party".
At the end of 2017, in an unprecedented move, the European Commission launched legal action against the Polish government, regarding a series of judicial reforms that were seen as a direct attack on democratic rights.
Along with Hungary, Poland has emerged as a massive headache for Brussels, due to its refusal to take large numbers of refugees over security fears, citing the spate of attacks across the UK, France, Germany and Spain.
Warsaw and Budapest have placed themselves at the forefront of what they describe as a "cultural counter-revolution" to power in Brussels, and have repeatedly fought against deeper integration in eastern Europe.
One of the largest net recipients of EU funding, Poland receives approximately €10bn (£8.9bn) a year from Brussels, but that money could be lost – should the EU implement cuts spending in its seven-year budget from 2020 to plug the gap left by Britain's exit.
Earlier this week, Jean-Claude Juncker, the president of the European Commission, warned the remaining 27 European Union members that they will have to pay more to fill the €13bn hole Britain will leave in the bloc's annual budget after Brexit.
That could potentially mean that Poland, whose economy has been thriving recently, could find itself paying more to Brussels than it receives. According to Tusk, that scenario could well pave the way for a referendum in which Poles would have to decide whether they want to leave the EU.
"I can easily imagine a situation when Poland finds itself among the net payers, then the government in Poland would feel it was time to ask Poles if they wanted Poland to continue in the EU," he added.
Poland's former PM explained that while Brussels was still hopeful Warsaw would not follow Britain out of the bloc, time was running out ahead of the country's next general election, which will be held in three years.
"In Brussels there is still enormous hope — I won't say trust because that's already dead — that Poland will stay in the union," he added.