German chancellor Angela Merkel announced over the weekend that she will actively campaign for Sarkozy's re-election, though the French president has yet to formally announce his candidacy.

Hermann Gröhe, the general secretary of Merkel's Christian Democratic Union (CDU), said over the weekend that Merkel would "actively support Nicolas Sarkozy with joint appearances in the election campaign in the spring," The Guardian reported.

"France needs a strong president at its head, and...The UMP and France are in good hands with Nicolas Sarkozy, who has demonstrated foresight," Gröhe said, according to Le Figaro.

Merkel's announcement caught Paris by surprise, least of all because Sarkozy has yet to officially declare his candidacy, Business Insider reported.

"I did not know she voted in France," the French president said in an interview with multiple television channels on Sunday evening.

Sarkozy has not announced he will run for re-election.

It is a rare move for Merkel; European politicians tend to have an "unspoken pact" to not interfere with other countries' elections, according to the Guardian.

As Canadian magazine Macleans pointed out,

Pause here to consider what would happen if a sitting Democratic National Committee chairman had come to Canada last spring to announce Barack Obama’s participation in the coming election at Michael Ignatieff’s side. Or Jack Layton’s. Maybe he’d have flipped a coin. Anyway, you get the point.

However, though Merkel and Sarkozy are far from friends, the pair have worked closely to solve the euro zone crisis, and both leaders have a vested interest in keeping each other in office. They are often dubbed "Merkozy" for their close political cooperation, Deutsch-Welle reported.

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Socialist candidate Francois Hollande told public radio France Info that Sarkozy "has the right" to invite Merkel to France to support him, according to Deutche-Welle.

"If Ms. Merkel wants to come to France to defend the incumbent, she is totally free to do that," Hollande said. "If Ms. Merkel campaigns for the incumbent, I'm still going to work well with her when I'm elected in May."

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Merkel and her CDU party, the political equivalent of Sarkozy's UMP party, has made her distaste for the French Socialist party's plans clear.

"The Socialists are stuck in their dreams of the past. All they are doing is bringing out dusty concepts and wealth distribution fantasies from their moth-ridden policy cupboard," said Gröhe, The Guardian reported.. None of Hollande's "hitherto vague pronouncements" offered a solution to the problems of our time, he added, pointing to Hollande's proposal to lower the age of retirement.

The first round of presidential elections in France is April 22. Hollande leads Sarkozy with 56 percent support in the most recent polling, according to Deutche-Welle.