Thousands of protesters in cities across Germany have appealed to the government to accept refugees from the burnt-out Moria camp on Lesbos in Greece, amid government resistance.

In Berlin, an estimated 3,000 demonstrated under the motto: “We have room,” on Wednesday evening, condemning Moria as a “camp of shame” and calling for the resignation of the interior minister, Horst Seehofer, who has so far blocked the arrival of refugees.

In other cities, including Leipzig, Hamburg and Frankfurt, similar protests took place.

Seehofer has been under growing pressure for months to accept refugees from Greece, but has issued a nationwide veto on such a move.

German law requires that states and districts may only accept refugees if they have the agreement of the federal government. At least six states have joined an initiative to change the regulations.

But Seehofer and other leading conservatives such as Armin Laschet, leader of North Rhine-Westphalia, have insisted Germany should hold out and receive agreement from other EU countries first that they are also willing to take a share of the Moria inhabitants. Otherwise the government fears, it risks sending a message that Germany has an open door, and triggering a repeat of the events of 2015 when almost a million refugees arrived, the political fallout from which is still being felt.

The fires this week which have wiped out the camp and left its almost 13,000 inhabitants without shelter, have intensified the debate.

Some demonstrators on Wednesday gathered in front of the interior minister, chanting: “Evacuate immediately.”

Amid signs of rifts within Angela Merkel’s coalition government, on Thursday 16 MPs from her conservative alliance wrote a letter to Seehofer calling for him to allow 5,000 refugees to be taken in, if necessary without agreement from other EU countries.

“The terrible fire has further worsened the already catastrophic situation in Moria,” the signatories wrote. “The main priority should now not be to formulate a common European refugee policy, but to alleviate the obvious human need. We urge you to enable Germany to take – if possible together with other EU states, but if necessary also alone – 5,000 refugees from Greece.”

The development minister, Gerd Müller, also said Germany should take in 2,000 refugees, as a “sign of humanity”.

In total 170 German towns and cities have signalled their willingness to welcome refugees from Moria.

Events on Lesbos have also increased pressure on Merkel to change her government’s course. Having recently taken over the presidency of the council of the EU, Germany has stubbornly adhered to a long-term goal to secure a European solution, although the refusal from countries such as the Netherlands and Austria to take in Moria inhabitants has made it increasingly remote.

On Monday, before the fire in Moria, the pro-refugee initiative Seebrücke (Sea Bridge) assembled 13,000 white empty chairs in front of the Bundestag in Berlin under the slogan “we have space”, one for each of the Moria inhabitants, who it said had been “left to vegetate”, without adequate medical provision and no ability to physically distance.