You could be paying with other person's account as I'm concerned. Use Virwox.com to buy bitcoins with paypal, or just pull the funds from the account and find someone that sells them on localbitcoins.com and accepts cash.
Thanks for the suggestion, my brother has decided to pay with a £20 ukash voucher instead.
Nice to hear that, you can buy ukash vouchers with paypal on http://www.safevouchers.com, after that I can exchange them into bitcoins with my service, http://mercabit.eu/
Thank you!
Made this guide: www.bitcoinuk.blogspot.com
So far the cheapest way that I found to buy btc from UK..
Hope it helps.