Donald Trump cannot be found guilty of obstruction of justice because of the rights of the US presidency, his lawyer has claimed.

The US president is the “chief law enforcement officer” in the country and therefore free to express his views on all legal cases, John Dowd claimed.

The remark is the latest attempt to protect Mr Trump from the growing scandal about his campaign’s links to the Russians and how he acted after winning office.

Political opponents and the investigation being led by Robert Mueller, the former FBI director, are reportedly developing a case of obstruction of justice against Mr Trump.

Obstruction of justice is one of the grounds for impeaching a US president and helped bring down Richard Nixon, the former US president.