The deal has been posted before ( http://www.hotukdeals.com/deals/playstation-plus-12-month-for-31-99-electronicfirst-com-2542216)
but the £35 code is now cheaper at £30.99
Just in time for incoming Black Friday deals. Sony email says they'll be available from later tonight.
Some games may be cheaper to buy from the US store, so you may want to double check before committing to the UK store.
Either way, it's the cheapest way to top up the UK wallet at the moment (except the O2 sim trick but that's a different story)
Edit: £35 code is now out of stock, and £50 code is still available at £45
Edit: £35 code back in stock again