Police have identified 31 people suspected of playing a role in New Year's Eve violence in Cologne
German Chancellor Angela Merkel has backed a crackdown on convicted refugees after a wave of sex assaults and muggings on New Year's Eve were blamed largely on foreigners.
The reports of attacks on women in Cologne by gangs of men described by police as mostly of "Arab or North African" origin has ramped up pressure for stricter measures in Germany, which took nearly 1.1 million migrants last year.
Some 121 women are reported to have been robbed, threatened or sexually assaulted during New Year's celebrations near the city's twin-spired Gothic cathedral.
Speaking at a meeting of the Christian Democrats on Saturday, Mrs Merkel said: "If a refugee flouts the rules, then there must be consequences, that means that they can lose their residence right here regardless of whether they have a suspended sentence or a prison sentence.
"Serial offenders who consistently, for example, return to theft or time and again insult women must count on the force of the law."
She added: "This is in the interests of the citizens of Germany, but also in the interests of the great majority of the refugees who are here."
Under current laws, asylum seekers are only deported if they have been sentenced to jail terms of at least three years, and if their lives are not at risk in their countries of origin.
As well as reducing the deportation threshold, the proposal put forward by Mrs Merkel's party would also strengthen the ability of police to conduct checks of identity papers.
The move comes as supporters of the far-right group PEGIDA are staging a rally in Cologne in response to the attacks.
The city's chief of police has resigned over criticism of his handling of the situation, amid claims officers covered up the involvement of large groups of migrants.
The 31 suspects held for questioning following the New Year's Eve attacks, included 18 asylum seekers, two Germans and an American.
None were accused of specifically committing sexual assaults and the investigation is continuing.
Mrs Merkel has refused to agree to establish a cap on new arrivals, but the CDU proposal did note "a continuation of the current influx would overwhelm the state and society even in a country like Germany in the long run".