Organisers planned to march towards the headquarters of the CDU
Organisers planned to march towards the headquarters of the CDU AFP

Demonstrators descended on Berlin Sunday to protest the norm-shattering overtures by Germany's conservatives towards the far right as the country heads for a fraught election this month, drawing at least 160,000 people, according to police.

Organisers said 200,000 people had turned out to denounce the breach by the Christian Democratic Union (CDU) of Germany's unwritten agreement not to work with the far right at the national level, in place since World War II.

After the rally kicked off just outside the Bundestag, Germany's parliament building, some protesters chanted slogans including "Shame on you CDU" before moving on towards the party's headquarters.

Others accused the CDU, currently the main opposition party, and its leader, Friedrich Merz, of having made a "pact with the devil" by seeking the backing of the far-right Alternative for Germany (AfD) to pass an anti-immigration bill.

"(We want to) make as much noise as possible to call for the self-described 'democratic' parties to protect this democracy," protester Anna Schwarz told AFP.

The 34-year-old said she was joining a political rally for the first time as "we can no longer avert our gaze, it's too serious".

The CDU's canvassing for the far-right AfD's support in parliament last week sparked widespread fury in Germany, less than a month ahead of a snap federal election.

In doing so Merz, frontrunner ahead of the February 23 vote, broke the decades-old "firewall" set up in the aftermath of the horrors wrought by Nazi Germany.

The two parties successfully passed a non-binding resolution on Wednesday in an attempt to block undocumented foreigners at the border, including asylum seekers.

On Friday, they failed to pass a contentious bill to further restrict immigration -- yet the taboo had been broken all the same.

The 33-year-old self-proclaimed "queer militant" said she was reassured by the rally's turnout.

"Today, we need to show that there are more of us defending democracy than there are of them," she said.

Merz launched his all-out immigration crackdown after police arrested an Afghan man following a deadly knife attack a week ago against a group of kindergarten children.

He "wants to cut through" the norm of not working with "right-wing extremists in one fell swoop", said left-wing NGO Campact, one of the protest organisers.

Already on Saturday, more than 220,000 people had marched in cities across the country, including Hamburg, Leipzig, Cologne and Stuttgart, according to figures compiled by public broadcaster ARD.

Trade unions, civil society and rights groups, churches and environmental activists were among those to answer the call.

Centre-left Chancellor Olaf Scholz has warned that the conservatives and the far right could soon join forces to govern the country, as has been the case elsewhere -- including neighbouring Austria.

Even if Merz has rejected governing with the AfD, "he already betrayed his word last week," protester Matina Beibel told AFP. "So how can we trust him?"

Even Merz's predecessor at the head of the CDU, former chancellor Angela Merkel, branded leaning on the AfD a "mistake" in a rare rebuke from the veteran politician.

Merz has strongly criticised the AfD and vowed never to govern with it, while arguing that the immigration debate should not be dominated by the extremist party.

But he has promised an about-turn on immigration from the open-door policy of his more centrist predecessor and party rival Merkel.

His move comes after a series of deadly attacks that have darkened the mood in Germany over the arrival of millions of war refugees and other asylum seekers in recent years.

Merz, whose party is polling at 30 percent, is banking on going "all in" on immigration to peel away voters tempted by the AfD's strident anti-migrant policies.

Critics charge that this is a high-risk gamble that will only pander to the extreme forces in German politics, in a country still seeking to atone for the Nazi regime and the Holocaust.

The AfD is polling behind the CDU in second place with between 20 and 22 percent of the vote.

Police said at least 160,000 people had turned out for the protest in Berlin
Police said at least 160,000 people had turned out for the protest in Berlin AFP
The protesters accused Germany's conservatives of having made a 'pact with the devil' by seeking far-right backing
The protesters accused Germany's conservatives of having made a 'pact with the devil' by seeking far-right backing AFP
Protesters holding a banner reading 'We are the firewall. No cooperation with the AfD'
Protesters holding a banner reading 'We are the firewall. No cooperation with the AfD' AFP
Merz is banking on going 'all in' on immigration to peel away voters tempted by the AfD's strident anti-migrant policies
Merz is banking on going 'all in' on immigration to peel away voters tempted by the AfD's strident anti-migrant policies AFP