get legal advice. i think you're up shit creek though as fas as the landlords concerned, he can increase the rent reasonably as he see's fit. dont matter if they didnt come inside....i bet the value & therefore rent of the property has gone up over the last 3 years.

feel sorry for you as you're obviously good tenants, hopefully he will get idiots next time.

sorry i couldnt help but DEFFO go to your CAB (free) and maybe get some dialogue between you and your landlord about a reducing the increased.....rent will go up mate as does everything in life. I'd say you've done well to escape it for 3 years, ive known some to increase every 12 months.