Hi Camvan
When I was on Courier Exchange, (who called again toating for business just before Christmas) work being offered into EU was averaging about 85p plm. Out of shear devilment, I once priced a job at 69pplm and still didnt get the job. It has been said to me more than once "Well you will make your money on the return". Good thinking, but it been my experience that you don't always get a job back to where you'd like to be. Home. But end up in South Wales, Luton or Dagenham.
As pointed out by Mr. Affordable courier, You still have your return boat/train fare to consider and any tolls and FINES you might encounter. Roadside fines are usually payable on the spot.
Take Mr Barnsleys advice and try to locate your own customers, use Courier Exchange to advertise your whereabout in EU you might be, someone will call.
As for the Polish drivers. I've seen some of their company drivers bringing fuel over to top up the driver making his return trip. What you have to do is find a filling station near to your depature point back into the UK, Which sells fuel which, when you compare the price against UK prices is cheeper once you've deducted UK vat. Alternatively (and there may be some one on mtvan or Courier Exchange) you or your accountant can claim the duty back from what ever country you fueled up in.
Mr Legrys has a point, an O.D. I know in Leeds area lost his regular work when he was under cut by £200.