The poll, conducted by Republikon between March 16 and 18, put support for nationalist Orban's Fidesz at 41% of the electorate, up one point from February levels, while the opposition was unchanged at 39%.

Orban's path to re-election is complicated by Russia's invasion of Ukraine, which has put his decade-long close relations with Russian President Vladimir Putin in a new light.

Hungary will not send any weapons to Ukraine and will stay out of the war, Orban told a rally of his supporters last week.

Weeks after the Feb. 24 invasion, the poll showed 57% of respondents thought EU-member Hungary's allies were in the West rather than in the East.

Orban faces a united, six-party opposition front for the first time since taking office in a 2010 election landslide.

The opposition alliance includes the Democratic Coalition, the Socialists, liberals and the formerly far-right, now centre-right, Jobbik. Its candidate for prime minister is Peter Marki-Zay, an independent who is currently mayor of Hodmezovasarhely, a town in southern Hungary.

The ranks of the undecided were flat at 16%, according to Republikon. Among decided voters, Fidesz had 49% support, while the opposition alliance scored 46%.

Republikon said the outcome of the vote would depend on which side can mobilise its voters in the run-up to the election and which side can better appeal to the undecided. Republikon said 67% of the electorate said they would definitely vote.

Republikon also surveyed attitudes to the introduction of the euro to replace the forint - a key plank in the opposition's campaign - and said 46% of respondents were in support, while 31% thought it was unnecessary. Most Fidesz voters do not want the euro, while 79% of opposition voters would adopt the common currency.

DATE AGENCY FIDESZ OPPOSITION UNDECIDED

March 16-18 Republikon

39 16

41

March 2-11 IDEA 40 37 11

Feb 18-24 Republiko 39 16

n 40

Feb 22-26 Median 39 32 20

Jan 31-Feb 9 IDEA 38 34 13

Feb 2-10 Zavecz 38 36 20

Jan 20-25 36 34 22

Republiko

n

Jan 4-14 IDEA 39 37 10

Dec 4-7 Median 39 34 13

Dec 9-14 Republikon 33 36 24

Nov 2-12 Zavecz 37 41 14

Nov 2-3 Nezopont 56 42 2

Oct 25-29 Republikon 32 38 30

Oct 11-19 Zavecz 35 39 23

Sept 29-Oct 4 Median 37 37 17

Oct Szazadveg 50 44 6

Sept Zavecz 37 38 23

Sept 20-21 Nezopont 53 45 N/A

Aug 23-25 Nezopont 52 46 N/A

(Reporting by Krisztina Than; Editing by Nick Macfie)