Anti-racism protesters have been thrown out of Ukip's manifesto launch event.
Paul Nuttall was due to announce the party's platform for June's snap general election on Friday.
One of the protesters shouted: "Paul Nuttall wants to spread division. How dare he tell Muslim women what to wear?"
It followed the launch of Ukip's "integration agenda" which included a ban on face coverings like the burqa, as well as a plan for mandatory medical checks of schoolgirls deemed to be at risk of female genital mutilation.
According to Ukip, police have been called to remove the protesters from County Hall in central London.
There were five protesters, led by Weyman Bennett of Unite Against Fascism.
Ukip's foreign affairs spokesman, the West Midlands MEP James Carver, resigned after Mr Nuttall launched the integration policies earlier this week.
He said: "No one has the right to dictate what people should wear.
"When facial identification is necessary, such as at passport controls or in a bank, then it is perfectly reasonable to order the removal of veils, as is the practice, but in a free and liberal society, people have a right to their religious beliefs, and to dress as they see fit."
Launching the manifesto, Mr Nuttall claimed the Prime Minister was already rowing back on immigration promises and had refused to rule out paying a huge divorce bill from the EU.
The party leader insisted Brexit was a job "half done" and declared "we are only half way through the war".
Mr Nuttall said the party is prepared to stand aside in dozens of constituencies in order to help sitting MPs who are real Brexiteers hold on to marginal seats.
Accusing Ms May of "flagrant opportunism" in calling a snap election, he insisted Ukip would fight it with "vigour".
In a speech in central London, he said: "We also believe that a whopping Conservative majority will only serve to put Brexit in peril.
"Hordes of Tory lobby fodder will allow the Prime Minister to backslide safe in the knowledge that she has the votes banked.
"We are not convinced that the Prime Minister, who campaigned to Remain in the referendum, will get the deal the British people want.
"She is already beginning to backslide on immigration, with the Government now telling us that immigration will run at today's level for the next decade.
"She has said nothing to guarantee our waters and protect our fishermen and she will not rule out paying a huge divorce bill once we have left the European Union."
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