AMSTERDAM (Reuters) - The Dutch election has centered on the fight between the two hard right candidates, anti-Islam maverick Geert Wilders and Prime Minister Mark Rutte, but the leader of the Christian Democrats has crept to within striking distance of topping the poll.

CDA leader Sybrand Buma campaigns, the day before a general election, in Delft, Netherlands, March 14, 2017. REUTERS/Yves Herman

Sybrand Buma’s Christian Democratic Appeal (CDA) is all but certain to participate in the next governing coalition, regardless of who wins, and Buma even has a long-shot chance of becoming prime minister after Wednesday’s vote, given other parties’ refusal to work with Wilders.

The latest polls show the right-leaning, low-profile Buma trailing Rutte’s VVD by 4 percentage points and just 1 point behind Wilders’ PVV, on a rising trend. He could command around 20 seats in a fractured 150-seat parliament.

Since Feb. 24, the CDA has gone up in every one of the 11 polling updates in a poll of polls - the only party to do so.

Buma told Reuters all the pre-election talk had been that “this campaign would be about a rivalry between Rutte and Wilders. What’s left of that dual? We are getting stronger every day and the chance that we are the biggest on election day is very real, and no one is expecting it.”

Buma has gained ground by adopting a tough line similar to Rutte’s on immigration, adding a focus on communal values and a touch of nationalism to tap voter concerns about Dutch identity.

He has proposed introducing singing the national anthem in schools and mandatory community service, but supports remaining in the European Union and keeping the euro currency - albeit with some reluctance.

The CDA campaign is “very much about moral issues rather than economic issues”, Buma said. Compulsory social service for youths, he said, would help them see that society is “not only what’s in it for you ... but also what you give back”.

But while the CDA presence in government would ensure a conservative stamp on any coalition, Buma said it endorses freedom of religion “and that’s a great difference. We won’t govern with the PVV.”

TURKISH ROW

Buma supported Rutte’s decision to block Turkish politicians from addressing supporters of Turkish President Tayyip Erdogan among immigrants in the Netherlands ahead of a Turkish referendum. Both Rutte and Wilders have seen a bounce in the polls from the row.

Buma said Erdogan’s remarks referring to the Dutch as “Nazis” and “fascists” were behind the diplomatic crisis, in which Turkey said on Monday it would suspend high-level diplomatic relations with the Netherlands.

“That goes deep into the heart of the (Dutch) people,” he said. “My own grandfather died in a German concentration camp.”

Buma responded by calling for Turks with dual Dutch-Turkish nationality to give up their Turkish passports, a response that played well with voters.

“They have two passports, which is a problem indeed,” he said, adding that Erdogan’s assertions that he represents second and even third generation immigrants “has to stop”.

“We want to integrate Turkish Dutch people into our society,” Buma said.

Despite its support now, the CDA, a traditional powerhouse in Dutch politics, began suffering setbacks in 2006, as parts of its traditional voter base in the south and rural areas flocked to Wilders and his anti-Islam Party of Freedom (PVV).

In 2012, Buma was left leading just 13 members after commanding 41 in 2006.

But in opposition, Buma proved himself a good debater with an unexpected flair for humor and has played up the parts of the Christian Democrat platform that appeal to voters who defected to the PVV.

“In my view that’s because the themes that have come to the surface, identity, values and norms, immigration and immigration, are our themes,” he said.

He said he was focusing on the more rural south and southwest of the country, where the CDA has a strong presence at a local level and leftist and secular parties hold little appeal.

“They are disappointed in Wilders there and people like to choose candidates that come from their own area,” he said.

“I have the impression that we could have a huge bump there.”

(The story was refiled to show Buma’s grandfather died in a concentration camp, not his father)