Merkel's challenger seeks to kick-start election campaign, says chancellor isolating Germany

Chancellor Angela Merkel's challenger has accused the German leader of isolating the country in Europe as he seeks to kick-start his campaign for elections next year, pledging to make social policy and promises of tougher financial regulation central issues.

The center-left Social Democrats held a special party convention Sunday to elect former Finance Minister Peer Steinbrueck officially as their candidate to take on Merkel when Germans elect a new Parliament next fall.

Party leaders nominated Steinbrueck in September. The Social Democrats are trailing in polls and Steinbrueck's start has been marred by controversy over his high earnings for giving lectures in recent years.

The 65-year-old Steinbrueck said taxes for top earners need to go up to finance spending on education and infrastructure but stressed that keeping down debt is essential.