Croatia's conservatives have elected a new leader who they hope can restore the party's image ahead of snap parliamentary elections in September.

The Croatian Democratic Union party, or HDZ, late Sunday overwhelmingly backed former diplomat and EU Parliament member Andrej Plenkovic as the new president. Plenkovic, who led Croatia's accession negotiations with the EU, promised to work to "regain voters' trust."

The Sept. 11 vote was called after the previous conservatives-led government fell amid a deadlock triggered by a dispute within the ruling coalition and allegations of conflict of interest against former HDZ leader Tomislav Karamarko.

The HDZ led Croatia to independence from the former Yugoslavia and ruled for years — alone or coalition — after the war of the 1990s. Croatia joined the EU in 2013.