Latest opinion polls conducted just days before the election unanimously forecast that 62-year-old Merkel, who has been in power since 2005, will remain at the helm of the next government irrespective of which coalition will be formed after the election.
Merkel's conservative bloc, that comprises her Christian Democratic Union (CDU) and its Bavarian ally Christian Social Union (CSU), will emerge as the largest group in the next Bundestag - the lower house of parliament - and no coalition will be possible without the conservatives.
They will have the best chance to form the next government picking their preferred partner, according to opinion polls.
The two parties together are expected to poll around 37 per cent of the votes on September 24 compared to 20 per cent forecast for Merkel's main challenger Martin Schulz and his Social Democratic Party (SPD).
Schulz has been lagging far behind Merkel in opinion polls during the past several months and he lost more ground after the only televised debate of the election campaign between the two main contenders three weeks ago.
Schulz, who until January was president of the European Parliament, no longer poses a threat to Merkel's re-election aspirations.
Only around 25 per cent of voters interviewed in opinion polls favoured him as the next chancellor compared to more than 50 per cent who wanted Merkel to remain in office.
Opinion polls also unanimously forecast that the anti- migrants far-right party Alternative for Germany (AfD) will enter the Bundestag for the first time in Sunday's election while the liberal Free Democratic Party (FDP), which lost its parliamentary representation in the last general election in 2013 for failing to poll the minimum five per cent of votes, will re-enter the lower house.
The AfD, which is forecast to receive upto 12 per cent of the votes, might become strong enough to replace the Left party as the third largest group in the Bundestag after the conservatives and the Social Democrats, according to the polls.
Public support for the Left party has been steadily eroding in the past months and now it can hope of receiving only around nine per cent of the votes.
The most likely outcome of the election predicted by opinion polls will be a new edition of Merkel's current "grand coalition" between the conservatives and the SPD, which is also the choice of a vast majority of the voters.
The polls showed that over 60 per cent of those surveyed are satisfied with the performance of the government during the last four years and they want the "grand coalition" to carry on its work in the next legislative period.
The conservatives and Social Democrats will have a comfortable majority in the next Bundestag which is necessary to ensure a stable government.
Arithmetically, a coalition between the conservatives, the Green party and the Free Democratic Party also could be possible, polls said.
However, there are strong political differences which still kept them apart and such a coalition at the national level has never been tried before.
Election analysts said around 50 per cent of voters are still undecided about whom to vote for on Sunday and therefore the election result will be influenced by the way the undecided voters would cast their votes.
Many voters interviewed said they will take a decision during the final phase of the campaign or just before the voting gets underway.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)