You are joking?

Even a quick look on Autotrader can find lots which should be affordable to insure:

Daewoo Matiz (should cost < £1000 for even a low mileage example)

Seat Arosa

Hyundai Accent

Skoda Felicia

Subaru Justy

Suzuki Swift 1.0 or 1.3

Or look for something > 10 years old for < £1000 and insure Third Party and run your NCB up. Check this for example:

Merecedes 190E Auto