Tory MPs fear a cover up over the 'Abba party' in the Downing Street flat after Sue Gray admitted she did not fully investigate the gathering.
Her long-awaited report into the Partygate scandal admitted her information on the event was "limited" as she had stopped when the police probe began.
After Scotland Yard wrapped up its inquiry last week she decided it was "not appropriate or proportionate" to carry on looking at the event.
