L Reg Nissan Micra Starting Trouble?

hi,
I have a very peculiar and strange problem with my L reg nissa micra....and this problem surfaces only during winters...in the cold winter mornings the car engine turns but just doesn't fires up...as the day progresses and the temp goes up with sun and all, the engine fires up...also I have observed that the fuel pump switching on sound which comes up when u turn the ignition is missing when I try doing the same in the cold winter mornings....I have been going mad over this issue and have got everything else checked and changed like the...engine oil, spark plugs and even the distributor....still the problem of cold start in the mornings persists...and its just in the winter mornings....in summers there is no problem at all...already have spent more than £200 on the services....plz help...thanks.