car smoking when starting

[whirly]

I have a peugeot 206 51 plate iit is a diesel i have to turn the key 3 or 4 times before it will start and when it starts it vibrates and has blue smoke coming out of the exhaust after about 5 minutes it seems ok i keep it in the garage over night it also happens when i get in to it after work and start it up can anyone help me