The Prime Minister has refused to say whether he will give Alun Cairns his job back as Welsh Secretary should Mr Cairns regain his seat as an MP in the general election.
Boris Johnson was asked repeatedly about Mr Cairns' cabinet position but instead said "Alun's standing at the election and I'm sure he'll do a great job".
Alun Cairns resigned as Secretary of State for Wales in November, the day the election campaign began, after claims one of his aides was involved in 'sabotaging' a rape trial.
Guto Harri asked Mr Johnson why he would not say if Alun Cairns can have his job back to which the Prime Minister replied, "What we're doing is campaigning as a united party but also as Welsh Conservatives."
The interview was carried out when the Prime Minister came to Bangor-on-Dee to launch the Welsh Conservative manifesto.
In the same interview, Mr Johnson also blamed slow progress on Brexit as to why there is a lack of public trust in politicians, saying Parliament is "broken".
When asked why people do not believe him, Mr Johnson cited his political track record as Mayor of London to try and prove he is a man of his word.
Look at what we said we would do and look at what we did. We said we would cut crime, we ended up cutting the murder rate by 50 per cent. We said we'd invest in transport and infrastructure, the biggest investment in transport and infrastructure you've ever seen and we did absolutely everything.