"Hungary's place is in Europe, not just because Hungary needs Europe, but because Europe needs Hungary," he said at the Tisza party's election kickoff in Budapest on Sunday.
The message stands in stark contrast to Prime Minister Viktor Orbán's words when the ruling Fidesz party launched its election campaign on Saturday.
"We must get used to the idea that those who love freedom should not fear the East, but Brussels," Orbán said, referring to Russia and the EU.
Magyar also promised an end to corruption and a turnaround for the economy, which he believes is "stuck in a dead end."
Tisza has a tailwind in public opinion ahead of the parliamentary elections on April 12.
