An FBI agent who sent anti-Trump messages while working on the Russia investigation has been fired by the intelligence agency.

The politically charged text messages between Peter Strzok and Lisa Page, an FBI lawyer, caused uproar among Republicans who claimed it was proof the investigation into Russian collusion was politically motivated.

Mr Strozk was removed from Special Counsel Robert Mueller's investigation after the messages were discovered.

On Monday Aitan Goelman, Mr Strzok’s lawyer, said the FBI's Deputy Director ordered his client's dismissal on Friday - despite the fact that the agency's disciplinary office had ruled Mr Strzok should face a demotion and 60-day suspension.

Mr Goelman told the Washington Post the firing went against the FBI’s repeated assurances that Mr Strzok would be afforded the normal disciplinary process.

“This isn’t the normal process in any way more than name,” Mr Goelman said.

Mr Strzok and Ms Page sent a series of messages railing against Mr Trump as a candidate and after the 2016 vote - while they both worked on the Russia investigation.

In one exchange in March 2016, Ms Page refers to Mr Trump as a "loathsome human" with Mr Strzok responding, "Yet he may win," later saying, "America will get what the voting public deserves."