2002 1.4 polo SE not always starting

Hi Im writting about my 02 Polo that isn't starting first time every time. Its done 100000km and just had major service and cam belt replaced. The polo had its problem 25% of the time before the services, and 2 months after major service it's misfirering almost 90% of the time and is using a lot of fuel when attempting to start it. If it does start its an uneven idol at first and then it usually stalls and once it does stall it kicks over straight away and drives perfectly. Could it posibly be a relay problem? Any help on this issue would be greatly appreciated.

Hello, I am not a Polo owner , however I am real suspicious of your 100,000 km ignition key switch. They are located in the steering column, and are a bit difficult to replace. They are a complex plastic and brass mass produced part. Its a dealer item . Thats one possibility. Allan