Britain's Conservative Party politician Boris Johnson has placed a bet against Shane Warne that will wear an Australian jersey for 24 hours if he England loses the Ashes to Australia.

The Mayor had placed this bet before the Ashes started while playing an impromptu cricket match to encourage volunteering.

Johnson's bet appears to be safe as England have taken control of the series with a 1-0 lead going into the second Test at Lord's. The home side clinched a classic 14-run thriller at Trent Bridge which saw the momentum swinging from one to another across five days.