Does anyone know what this plant is?

This plant is rapidly taking over, growing in the borders, cracks in paving and pots.  Does anyone know what it is?  I wondered if it was a form of campanula.  It climbs and trails.  The photo makes the flowers look blue but they are more purple.

Muddy, Looks a lot like Vinca Major or periwinkle a vigorous sub shrub the five petals and glossy leaves remind me of it but then I could be wrong.

Frank.

http://www.english-country-garden.com/flowers/trailing-bellflower.htm

It's a trailing campanula, we've got it growing everywhere we let it.  If you pull it out it'll reappear next year.

Thanks for your responses.  Having followed the link my flowers are more a purple colour but I do think it's very likely to be a campanula.  I shall apply my usual containment methods.  It's a shame it's got into the block paving as this is a real pain to keep looking tidy.

It's a Campanula Portenshlagina- I had the same problem- you have to dig out ALL the roots that go quite deep or it will just grow back again and smother everything. Make sure you get every last bit !!

Haven't tried the glyphosate on it so let me know if you have any luck with that. It spread all over my rockery and I had to basically take the whole thing apart and tediously pull each piece of root out, put the whole thing back together again and replant with new plants! I wish I had not planted it in the first place ! Ahh well- we live and learn !

Glyphosate will work!

Flamethrower might be my solution then.  Thanks for everyone's help

Will have to go down the chemical route on the block paving then.  It can stay in a limited border area as it is pretty and seems to one of a few plants that can cope with living beneath my leylandii hedge.  Crocus charge £6.99 per plant!!

The thing is they spread by seed as well as sprawling 

Well, seeding is the problem of course, so one shot won't do the trick.

That is the beauty of these boards we learn something and gardeners never stop learning. Having had trouble with Vinca before it came to mind, Campanula was Carpatica, Glomerati, Isopbila or Japonica, I had never heard of that form Muddy managed to produce. Climbing Bellflower now goes in my no-no book.

Frank.

It comes in a pink variety, as well, so the purple may be a cross between that and the blue.

.... but in the right place under control it is absolutely gorgeous! Most of the other campanulas are not quite as invasive, but there is a tall white one, the name of which escapes me at present, and that really has become a pain in the front garden - sets itself everywhere, I'm actually encouraging the little blue one as that is low enough to be manageable, but the white one is really a pest in bellflower clothing.