My dads car has been doing this quite badly lately, it does need a service so I am hoping it could just be that but I can't see changing the oil and plugs will solve it.
The engines often done this, the first time it was a faulty lambda sensor causing it, the second time my uncle cleaned out the idler valve which solved the problem for about 2000-3000 miles but now its come back again.
The car is also quite jerky but that can just be put down to it needing an oil change and new plugs, its an 86,000 mile Escort (last shape) 1.6 Zetec LX.