Donald Trump has said he will announce his choice for a running mate this week, in advance of the start of the Republican National Convention on Monday.

Here is a look at one of the four men most likely to join Trump as a vice presidential candidate – Mike Flynn.

Mike Flynn

Age: 57

In August 2014, Flynn left his job at the Defense Intelligence Agency, allegedly after clashing with officials in the Obama White House.

Flynn is more to the left than others being considered for the job of Trump's running mate. When asked about same-sex marriage, Flynn said, "What people do in their private lives, these are not big issues that our country’s dealing with."

What they are saying about Flynn

Flynn is a Democrat

Politico

National security chops

CNN

The Associated  Press contributed to this report.