BUDAPEST (Reuters) - Support for Hungary’s ruling nationalist Fidesz party has fallen behind an alliance of opposition parties, a poll by research institute Republikon published on news site Telex.hu showed on Wednesday, reflecting similar recent polls. Prime Minister Viktor Orban, who has held a chokehold on power since 2010, faces his toughest election in 2022 as the coronavirus pandemic and its economic effects linger and as opposition parties grouped together against him. Fidesz has been embroiled in conflicts at home and in the European Union as the premier vetoed the 27-nation bloc’s 1.85 trillion euro ($2.25 trln) budget and recovery package, ignoring criticism from his domestic opposition. Fidesz also suffered as it was hit by a major scandal with a senior EU lawmaker resigning after he fled a Brussels orgy in violation of lockdown rules and in possession of illegal drugs, according to Belgian authorities. Following months of talks, six major Hungarian opposition parties agreed on Sunday to hold primary elections for the first time in a national vote and challenge Fidesz one-on-one in all voters districts, behind a single leader and a single programme. Their cumulative support has grown to 35% of all voters in the December 8-15 poll from 32 percent in November, Republikon found, while Fidesz slipped to 30% from 32%. Other pollsters have measure similar trends. Fidesz support fell by 6 percentage points in a single month to 34% in December, Median said last week, while the opposition added 2 percentage points and took over Fidesz at 36%. Zavecz Research also said earlier this month that Fidesz support fell to 30% among all voters while the opposition had the backing of 34%. Even pro-government pollster Nezopont said last week that while support for Fidesz was at 42% of all voters, up from 40% in its last public poll in July, the opposition narrowed the gap to score 40%, up from 31% in July. ($1 = 0.8216 euros)