BERLIN (Reuters) - Support for German Chancellor Angela Merkel's conservatives has risen to its highest level in two years in North Rhine-Westphalia, Germany's most populous state, albeit on a par with its main opposition, a poll showed on Sunday.
The Infratest dimap poll, conducted for broadcaster WDR, showed the Christian Democratic Union (CDU) adding four percentage points to reach 34 percent, while the Social Democrats (SPD) dropped three percentage points, also to 34 percent.
That was the best result for the CDU since December 2015. It was the first time that the two parties stood neck-and-neck in the polls since October, when they both had 31 percent support.
The state is currently governed by a SPD-Green coalition.
Voters in the state go to the polls on May 14 in what could be a bellwether for national elections in September. A strong showing for the CDU in the state could bode well for Merkel's bid to secure a fourth term.
The latest poll showed a one-percentage point drop for the anti-immigrant Alternative for Germany (AfD), which is poised to head further to the right after a controversial party congress in Cologne, in the heart of the state.
The pro-business Free Democrats (EDP) gained one percentage point to 10 percent, while the pro-environment Greens remained unchanged at 6 percent and the Left party was at 5 percent, with just enough votes to win seats in the state parliament.
If the election were held now, the ruling SDP-Green coalition would not have enough votes to rule, and even a "red-red-green" coalition including the Left party would not be possible.
Infratest dimap surveyed 1,000 eligible voters April 18-20.
The poll raised further doubts about the "Schulz effect," a sharp rise in the polls for the centre-left SPD after the party nominated former European Parliament president Martin Schulz to challenge Merkel in the Sept. 24 national election.
The SPD party also lost support in a vote in the Saar state in March, compared with its results in 2012.
Norbert Roettgen, a member of the CDU and head of the parliamentary foreign affairs committee, told broadcaster Deutschlandfunk that Schulz's gains were "turning out more and more to be a flash in the pan" rather than a substantive shift in the German electorate.
Reporting by Andrea Shalal Editing by Jeremy Gaunt.