A senior female politician has attacked calls for German women to change their behaviour in the wake of the mass sex assaults on New Year’s Eve by declaring “Without the dirndl and the mini-skirt, this is not my country.”

Angelika Niebler, executive vice-president of the Christian Social Union (CSU) – which is in permanent alliance with Angela Merkel’s Christian Democrats (CDU) – said in an interview with Die Welt that women should not have to “adjust their behaviour” after hundreds were subjected to sexual assaults at the hands of migrant men.

“Those who come here must respect our values,” she said. “In Bavaria, women will continue to wear dirndls [traditional German dress] and mini-skirts. If that is no longer assured, then this is no longer my country. A piece of identity is lost.”

She was responding to comments from Cologne’s mayor Henriette Reker, who said women should be more careful after the attacks: “The women and young girls have to be more protected in the future so these things don’t happen again.

“This means, they should go out and have fun, but they need to be better prepared, especially with the Cologne carnival coming up. For this, we will publish online guidelines that these young women can read through to prepare themselves”.

Ms Niebler said it took her a few days to come to terms with the scale of the New Year’s Eve attacks as should could not believe authorities could cover up such a massive event.

“One reason is that I could image the police would hide it,” she said. “The same evening in Munich we had a terror alert and the police took full control of the situation. I was convinced that on New Year’s Eve all major cities would have enough police on duty and, if necessary, reinforcements.”

Implementing a limit on immigration into Germany is now “imperative”, she added, and with 4,000 migrants arriving each day “we will be overwhelmed in a few months”.

Asked what the solution may be, she said that Germany may soon have to adopt Sweden-style border checks:

“If international action does not lead to a reduction in the number of refugees in the next two to three months, we must seriously consider such measures,” she said.