I am sure this is going to be a controversial one, what with all the stuff about tax, etc. And I don't normally encourage or promote credit cards.
However, I did notice upon checking out that Amazon have launched a new credit card. It's a Platinum mastercard that awards you £10 Amazon credit upon acceptance. During application, they even give you an idea about whether you qualify (not quite sure it amounts to pre-approval though).
Also you get an immediate £500 instant spend at Amazon - I am sure this amounts to a nominal credit limit/amount until your card is up and running.
You also get 1.5 Amazon reward points per £2 spent. And 1 point elsewhere.
It probably compares badly with others for interest rates. But the £10 giftcard has to be worth applying.