The German interior minister Thomas de Maiziere vowed revenge on EU fellow states over their part in the refugee chaos, accusing the rest of Europe of trying to „shift the collective problem onto our back”.
The extreme outburst highlighted the huge rifts opening up between European countries as the Brussels project lurches closer to collapse under the pressure of unprecedented migration.
Europe has been paralysed by indecision and bitter infighting over who should take the blame for the current refugee crisis, which has seen millions of people from Asia, the Middle East and North Africa arrive in the continent.
And Germany – which has descended into chaos after taking in by far the most migrants – finally snapped and issued an extraordinary rebuke to fellow member states.
In a furious outburst Mr de Maiziere said: „We will continue to fight for a European way out of the refugee crisis as long as it also promises to be successful in diminishing the number of refugees.
„However, should some countries try to unilaterally shift the collective problem onto the back of Germany, it would be unacceptable and would not be without consequences from our side in the long term.”
His comments could be construed as a thinly-veiled swipe at neighbours Austria, which has introduced a highly controversial cap on the number of asylum seekers it will accept each day.
Most migrants arriving in Europe via Greece or Italy immediately travel north, heading towards Germany, Austria, Sweden and Britain.
If Austria starts refusing to take in migrants that could have a huge knock-on effect on Germany, adding vastly to the almost 1.5 million refugees the country has already taken in over the last year.
Addressing the Bundestag, Mr. de Maiziere insisted his government will also „deal more harshly” with migrants who claim to be refugees fleeing war, but later turn out to have moved for jobs and benefits.
He also insisted authorities will clamp down on migrants who try to prolong their stay in Germany on false pretences, including those who launch spurious legal claims despite being found to have travelled their illegally.
Mrs Merkel has faced a furious backlash against her leadership in recent months as communities across Germany struggle to cope with the vast influx of newcomers.
The Politbarometer survey for public broadcaster ZDF showed more than a third of Germans were against such controls. Concerns about integration of migrants in German society are also on the rise, with the poll showing that just over half of Germans doubt it will be possible.
Slightly more than one in two think Germany cannot cope with the numbers of migrants arriving. The government expects hundreds of thousands more to come this year.