SPD politician Malu Dreyer says it is unimaginable for social democrats that the AfD should be the official opposition in Germany with all that that entails.

Inside AfD HQ in Berlin's Alexanderplatz, the noise from protesters outside the building is very audible.

Police gave permission for a 500-strong protest, and the demonstrators are making their presence felt.

As the CDU and SPD have both lost ground, four other parties have gained, so for the first time since the war Germany will have six parties in parliament. Die Linke (The Left), who are set to become the third biggest party in the east, are celebrating an overall result of around 9%. This is what the chair of the party thinks:

"We've got our second-best result in history and are going to fight with clear, socially-aware opposition against the right and for a new left-wing majority."

Broadcaster ZDF says that only the "grand coalition" of CDU/CSU and SPD - which has already been ruled out by the SPD - or the so-called "Jamaica" combination of CDU/CSU, Greens and FDP will reach enough seats to get a majority.

So it looks like it might be "Jamaica" or bust, using the colours of the three parties involved.

The combination of the black CDU with the yellow, pro-business, liberal FDP would fall well short of the 316 seats the broadcaster predicts would be necessary for an absolute majority in the new Bundestag. So they would need help from the Greens. Not an easy square to circle, though, as the Greens and liberals have very different agendas.

Look at this snapshot of analysis by public broadcaster ZDF: it shows that the right-wing nationalist AfD was the preferred party for men in the former East Germany. Some 27% of men in eastern Germany backed AfD - three points ahead of the CDU and well ahead of the other parties.

Image source, ZDF

Christian Lindner, leader of Germany's pro-business FDP, says that his party has yet not received an invitation to hold talks with the CDU/CSU, but would of course accept such an invitation.

In an implicit criticism of centre-left leader Martin Schulz, he says it is not for one party to say that the others must form the government.

What have we learned since the first projections came out just over an hour ago?

The centre-right have won under Angela Merkel, who has secured a fourth term as chancellor.

But, if confirmed, the 32-33% the CDU/CSU has won is its worst result under her leadership.

Her previous coalition partner, the centre-left SPD, has fallen to a historic low with around 20% of the vote. Leader Martin Schulz says he will now lead Germany's opposition.

Right-wing nationalist Alternative for Germany (AfD) is celebrating its entry into the Bundestag in dramatic fashion. They are heading for 88-89 seats, latest projections say.

The liberal, pro-business FDP is back in parliament after a four-year hiatus.

As it stands, Mrs Merkel's best bet of securing a coalition is with the FDP and the Greens who polled 9-9.5%.

The chancellor has promised to "draw the necessary consequences" and set about winning back voters from AfD.

All the senior SPD figures on stage with him were in agreement on that, the SPD leader added. That appears to put an end to any CDU ideas of reforming a "grand coalition".

Peter Altmeier, Chancellor Merkel's chief of staff, tells ZDF that his party is not ruling out working with the SPD, and says that they will approach all possible coalition parties.

Angela Merkel speaks of an "extraordinary challenge" for Germany and vows to listen to nationalist voters' concerns.

We want to win back AfD voters through good policies, Angela Merkel tells supporters.

This is an idea of what the election result as forecast will mean for the German parliament.

Mrs Merkel refers to future coalition talks "with other partners", and implies there is no rush to form a new government.

This is the view from the head of the German Institute for International & Security Affairs in Berlin:

After 12 years of the responsibility of government, it was not automatic that her party would be the largest party, the chancellor says.

The entry of AfD into the Bundestag brings challenges, she adds.