STRASBOURG (Reuters) - Former Finnish prime minister Alexander Stubb declared his bid on Tuesday to succeed Jean-Claude Juncker as EU chief executive, becoming the second candidate to lead the center-right in European Parliament elections in May.

FILE PHOTO: Finland's Finance Minister Alexander Stubb waves as he arrives at a European Union finance ministers meeting in Brussels, Belgium, December 8, 2015. REUTERS/Francois Lenoir/File Photo

Stubb wrote in a letter to fellow members of the European People’s Party (EPP) that he was a “declared pro-European” who had decided to run to defend European values and to push Europe to fill a power vacuum left by the “voluntary marginalization” of the United States and Britain from world politics.

“It is time to rally around our cause for a strong Europe. This means mitigating unnecessary divisions between East and West, North and South. We must be better at highlighting what unites us instead of what differentiates us,” he wrote.

Stubb, 50, has been prime minister, finance minister and foreign minister of Finland and is currently a vice president at the European Investment Bank.

The EPP, the largest trans-national group in the EU legislature, will choose its election leader at a meeting in Helsinki on Nov 7-8. Stubb will challenge Germany’s Manfred Weber, head of the EPP group, and possibly other conservatives.

The only other declared candidate is Slovak Socialist Maros Sefcovic, who is Juncker’s vice president for energy.

The European Parliament has demanded that the European Commission president should be one of the parties’ lead candidates, as happened for Juncker in 2014. Polls show that the EPP is likely to remain the biggest group in the chamber.

However, French President Emmanuel Macron and other leaders, who would actually nominate Juncker’s successor, oppose the automatic linkage between the EU election and the Commission job.

In this case, the leaders could select someone to head the Commission who is not one of the parties’ picks, although that person would still need to be approved by the parliament.

With a host of other EU posts to be filled in the coming year, notably that of European Central Bank President Mario Draghi, government leaders are engaged in a delicate game of strategy over which to seek for compatriots or political allies.

The EU parliament vote, held against a backdrop of Brexit and increasing nationalist complaints against Brussels in other countries, will determine the make-up of an important element in making laws applied across the continent.