By Andreas Rinke and Holger Hansen BERLIN (Reuters) - German politicians from across the political spectrum backed Chancellor Angela Merkel's firm line in aid talks with Athens on Monday despite the growing risk of a Greek default that could push it out of the euro zone. A day after negotiations between Greece and its euro zone creditors broke down, members of Merkel's conservative party accused Athens of losing touch with reality. "In our view, the Greek government is behaving increasingly irresponsibly, including towards its own country," said Yasmin Fahimi, general secretary of the SPD and a politician who has not shied away from criticising the government in the past.