BERLIN, June 2 (Reuters) - Germany's Social Democrats expect difficult talks with their coalition partners, Chancellor Angela Merkel's conservatives, on a stimulus package as they want cash incentives to buy a new car to exclude combustion engine vehicles, the SPD's co-leader said.
"It will take a long time and probably will not end today," Norbert Walter-Borjans said after an SPD spokeswoman said that a final decision on the stimulus package would be postponed from Tuesday to Wednesday.
"There are packages that can be agreed on... but there are also things the CDU and CSU have problems with, for example always when it comes to small or medium-sized incomes," Walter-Borjans said.
"And there is a big topic that we need to talk about, namely that from our point of view, there cannot be a purchase premium for cars with combustion engines," he added. (Reporting by Michael Nienaber, editing by Thomas Escritt)