Tory chairman Nadhim Zahawi is fighting for survival after an explosive row over his tax affairs.
The multimillionaire former businessman admitted to a "careless and not deliberate error" related to shares in YouGov, the polling firm that he co-founded.
Mr Zahawi reportedly paid a multi-million pound penalty to resolve the dispute with HMRC last summer, when he was Chancellor, meaning he was in charge of the UK's tax policy.
