Paying monthly works out as a bigger premium though doesn't it? Why should he have to pay for Greenlight's incompetence?
I would investigate getting temporary insurance, although i would probably just do what edde has said!
I'm gonna get cover for 2 - 3 days from DayInsure just to cover xmas - 27th/28th, to be on the safe side.
For the sake of 30 quid I'd rather be insured. Maybe I could try and claim it back from Greenlight if they do decide to help me.