AlQa'dah 15, 1434, Sep 21, 2013, SPA -- Chancellor Angela Merkel urged her Christian Democratic supporters Saturday to redouble their efforts in Germany's election, where her current parliamentary majority is on a knife-edge, according to dpa. "Get back into the fray. Start canvassing again," she told the rank and file of her centre-right party during a rally in Berlin. "I am personally appealing to the Germans: grant me a strong mandate so I can serve Germany for another four years." Pollsters say Merkel's Christian Democratic bloc (CDU/CSU) is likely to again win the biggest share of votes, about 40 per cent, but support for her current Free Democratic (FDP) coalition partners will slump from 15 per cent four years ago to about 5 per cent. That may not suffice for a parliamentary majority, prompting Merkel to turn to the opposition Social Democrats (SPD) to replace the FDP as her partner. She has hinted that she is ready for a "grand" coalition of the two big parties, but has avoided explicitly saying this is Plan B. Merkel told the Berlin crowd that a coalition with the FDP was her preference. Her previous 2005-09 grand coalition with the SPD had also coped well with the issues, she said, "but we were more successful in the Christian-FDP coalition." The Social Democratic (SPD) candidate for chancellor, Peer Steinbrueck, was booked to make a final campaign appearance in Frankfurt. His party is forecast to take a distant second place with 26-28 per cent of the vote. Even with Greens Party support, his group is not likely to be a match for the CDU/CSU. Steinbrueck has said he will not serve as a minister under Merkel, but has hinted he wishes to lead any delegation negotiating on a coalition. The chancellor was set to make one final public appearance Saturday afternoon in her own constituency, speaking to a crowd at Stralsund on the Baltic coast, before the campaign ends. She dismissed suggestions that she should sleep in on Sunday morning to recover from the ordeal of campaigning for four weeks, saying, "I'll be a bit on edge." Polling stations open in Germany at 8 am (0600 GMT) and close at 6 pm (1800 GMT) Sunday. The media are not allowed to broadcast exit poll results until the polls close. Unless the race is very tight, the outcome is likely to be clear Sunday evening within an hour or two, based on exit polls and the subsequent vote-count projections. Provisional final results are expected in the small hours of Monday.