BRATISLAVA (Reuters) - Slovakia’s member of the European Commission declared his candidacy on Monday to succeed Jean-Claude Juncker as the EU executive’s president, promising to try to ease tensions between western states and newer members from the ex-communist east.

FILE PHOTO: European Commission Vice-President Maros Sefcovic gestures during a news conference on Clean Energy package in Brussels, Belgium November 30, 2016. REUTERS/Eric Vidal

Maros Sefcovic, a Moscow-educated diplomat who is Juncker’s vice-president for energy, said he would seek the nomination of the center-left PES group in the European Parliament.

“I realize it’s a long and difficult process,” he told reporters in Bratislava, making the most public bid to succeed Juncker next year. “I will do everything to get the support of social democrat parties across the EU.”

Juncker’s successor must be agreed by leaders of European Union member states following elections to the European Parliament next May. Their nominee must also be confirmed by EU lawmakers before the new commission president takes over in November 2019.

The field of possible candidates is wide and the outcome hugely uncertain.

Sefcovic, 51, who has been in Brussels since 2004 as Slovak envoy and then commissioner, said a Czech delegation suggested he run during a meeting in Slovakia of center-left parties that also included Polish, Hungarian and Bulgarian groups.

“I will do my best to use this process to put the spotlight on stronger industrial policy, a more assertive position of the EU in international trade and on understanding between new and old member states,” he added.

The nationalist governments of Hungary and Poland in particular have been involved in a series of disputes with Brussels including over immigration and judicial independence.

CAMPAIGN

With center-left parties performing poorly, Sefcovic would face an uphill struggle to get the job even if he wins the nomination of the PES (Party of European Socialists).

However, he is a member of Slovakia’s ruling Smer party and therefore benefits from the backing of his own country’s government. By contrast, some other possible center-left candidates - such as Economics Commissioner Pierre Moscovici of France, EU foreign policy chief Federica Mogherini of Italy, and Frans Timmermans, Juncker’s number two from the Netherlands - are from countries where other parties hold political power.

Whoever wins the PES nomination will struggle to secure backing by a majority of national leaders on the European Council. The European Parliament is trying to force leaders to nominate a successor to Juncker from among lead candidates on party lists for next May’s EU legislative election.

Among other possible contenders widely cited in Brussels are EU’s Brexit negotiator Michel Barnier, IMF Managing Director Christine Lagarde and EU antitrust chief Margrethe Vestager, a left-leaning Danish liberal who also could not count on backing from her government at home.