German conservatives are preparing for formal coalition talks with Social Democrats (SPD) Monday shortly after the center-left party voted to break the months of political deadlock.

Chancellor Angela Merkel’s conservative Union bloc (CDU) and SPD of Martin Schultz are expected to open formal negotiation this week on extending their coalition of the past four years. 

Conservatives are warning, however, that they are not prepared to renegotiate preliminary agreements on such issues as migration.

Julia Kloeckner (Klöckner), a deputy leader of CDU, told ARD television Monday that the upcoming negotiations will focus on advancing of what was already agreed “but not bring up something that was already rejected.”

An SPD congress voted Sunday to pursue coalition talks with CDU, endorsing a plan agreed to earlier this month to compromise on issues such as health policy and the right of migrants’ families to join them in Germany.