Guardian journalist, Luke Harding, has been allowed to re-enter Russia after his expulsion from Moscow last week. The Russian officials have renewed his foreign journalist’s accreditation and he was able to obtain a single-entry visa on Friday. He returned to Russia the following day. Harding’s expulsion provoked extensive criticism, and British foreign secretary William Hague intervened.  The Russian authorities have claimed that Harding violated regulations which apply to foreign journalists, but Harding has rejected these allegations as pretexts.  Russian foreign minister, Sergei Lavrov, arrived in London today on a previously arranged visit.