Boris Johnson has arrived back in the UK for what is expected to be a bid to reclaim the Conservative leadership and win a second stint as prime minister.The BA jet carrying the former PM back from a Caribbean holiday touched down at Gatwick Airport at 10.19 on Saturday morning.Mr Johnson has yet to formally announce whether he will mount a challenge to succeed Liz Truss as Tory leader, but support Sir James Duddridge said he has been telling allies he is “up for it”.