Sajid Javid has reportedly started referring to himself in the third person during meetings with other ministers.
The Home Secretary calls himself ‘The Saj’ and ‘The Sajid’ while making assurances to his colleagues in Cabinet, a source told The Sun.
Mr Javid’s allies have said the claims are an attempt to discredit the 49-year-old, who is currently the bookies’ favourite to replace Theresa May as the next leader of the Conservative Party.
The latest odds put him ahead of rivals Boris Johnson and Dominic Raab.
A spokesman said that the story about Mr Javid’s nicknames for himself is ‘completely untrue’.
Mr Javid has come under criticism for his handling of the increase in migrants attempting to enter the UK by crossing the channel.
He was accused of making ‘illegal comments’ by immigration lawyers and refugee charities after suggesting that Britain could make sure claims from asylum seekers are ‘often not successful’ in order to dissuade others from attempting the cross-channel journey.
In a message to people planning to try and enter the UK, he said: “We will do everything we can to make sure it is not a success, in the sense that I don’t want people to think that if they leave a safe country like France they can get to Britain and then just get to stay.
“That’s why I am working out ways with the French to increase the number of returns that we can make to also send a very strong message that we will do all we can not just to protect human lives – of course that’s the right and responsible thing to do at all times – but also to protect our borders.”
The Home Secretary’s hardline stance on the arrival of migrants is widely seen as a move to position himself as the next Prime Minister.
Labour leader Jeremy Corbyn said that Europe cannot ‘close its borders’ to those genuinely seeking asylum.
He said: “They are the product of wars, they are the product of human rights abuses, they are the product of environmental disasters. Europe cannot close its borders to them.”