Alpha collapse: London cab drivers race to renew insurance
Thousands of London taxi and minicab drivers received a text message telling them their insurance had been cancelled.
Danish firm Alpha, which insured drivers through brands such as Cover My Cab and Protector, declared bankruptcy on Tuesday.
Up to 700 taxi drivers and 10,000 minicab drivers are affected, the Licensed Taxi Drivers Association said.
Queues were seen outside London's Protector offices on Wednesday.
Marci Moroney, a black cab driver who was in the queue, said he received a text saying he was no longer insured while he was working last night.
"I think this is one of the worst situations they have put us in... I had to stop work last night and now I've lost two days money," he said.
Another cab driver, Abdel Hamid, said he had been told he would not receive a refund, having paid more than £3,000 for a policy with the company over six months ago.
He said he had to wait in the queue to buy another policy "otherwise I can't work. My cab is parked outside my house."
General Secretary of the association Steve McNamara said: "We have notified all of our members about this change to ensure that no-one is unintentionally driving without insurance.
"We will be supporting any of our members that may have been affected."
Analysis by Tom Edwards, BBC London Transport Correspondent
When I asked one cab rep how serious this is, he replied: "Bad".
Although we don't know, some estimate this lack of insurance cover will affect thousands of taxi and minicab drivers.
What that means is they will not be able to work until they get more cover and this could affect livelihoods.
And it is unclear if those who had Alpha policies will get any money back.
There are already queues outside insurance broker offices who bought Alpha policies.
Experts say they have not seen problems with insurance for cabs and minicabs on this scale before.
Alpha operates in Denmark and is authorized to do business in all EU/EEA countries.
The company was placed into liquidation on 4 May and went bankrupt on 8 May.
The Danish Financial Supervisory Authority said those with a compulsory insurance policy must find a new insurance policy with another company "as fast as possible" to obtain their compulsory cover.
It is unclear whether drivers will be issued a refund for the remainder of their insurance period.
The British Insurance Brokers' Association said it was "a very serious situation" and had "immediately notified our member brokers" when it heard about the bankruptcy.
A spokesperson for the Association of British Insurers said all cab drivers should "double-check which firm is responsible for their policy so they can be confident they have the right cover in place".