Lack of power on my freelander tdi

Hi I have a freelander 2.0 tdi on a w reg
Its got full service history 147500 on clock ,yesterday I had a oil and filter change.
Right now I will get to the fault!! today when driving it keeps losing power when doing any speed but when i change gear it picks up for a few feet then dies again There is no smoke and no unusual sounds. any ideas???

I have just replaced the fuel filter but this as not made any differance to my problem.Please help!!!!

Tons of info on this if you do a few searches . I don't own a tdi so can't give much in the way of advice but I know that this subject crops up very often here. Best of luck.

I have tried searching but can only find information either on td4 or petrol freelander 1