I get those Vanquis offers. (They generally seem to target people with low credit ratings).
I'm reasonably confident that they'll give you a card (with a very low credit limit initially) but with very high interest rates. Of course, as long as you repay all (or most) of what you owe each month you won't pay a great deal of interest anyway but you'll still start to repair your credit rating.
At one time the big catch with Vanquis was that they applied a hefty annual charge to their cards but the most recent offers I've received have been for cards with no annual charge. (All the same, read the small print carefully before you sign up!).
Capital One would also be likely to offer you a Classic MasterCard:
http://www.capitalone.co.uk/creditcards/credit-card-range.jsf
Chris