Affair probe No 2...

JENNIFER and Johnson first met in 2011 – a year after he had been held to account over an affair with a previous mistress while he was Mayor of London.

A Greater London Authority report in 2010 ruled he should have declared an official interest regarding a City Hall adviser.

At the time, Johnson agreed to “bear in mind the definition of close associate in the future”.

But there is no known record of Mr Johnson disclosing any kind of relationship with Jennifer. A continuing GLA probe will look at whether she received preferential treatment and whether he acted with “honesty and integrity”.

A City Hall source said: “This is a very serious matter. If someone does something they don’t realise is wrong and agree to undertake training because they understand it is a proper thing to do, then they don’t have the defence of ignorance any more.”

A second insider added: “It’s important the whole truth is exposed – it stinks.”