The whistle blower who sparked Donald Trump's impeachment inquiry will have his life turned upside down when his identity is inevitably revealed, according to a former CIA agent.

Valerie Plame, who was forced to quit her undercover role when her name was leaked by US government officials in 2003, said her "heart goes out" to the CIA operative who raised concerns about a phone call between the US president and his Ukrainian counterpart.

In his complaint, the unnamed whistleblower said multiple officials on the call had raised concerns that Mr Trump had pressured a foreign government to interfere in US elections.

Since then a second individual, who has also chosen to remain anonymous, has come forward claiming to have first hand knowledge of the allegations outlined in the original complaint.

Mr Trump has rebuffed the claims, launching a counter-attack on the original whistleblower, who he claims is politically motivated.

With so much scrutiny upon him, Ms Plame told The Telegraph: "This person's life has changed forever; I think it's only a matter of time before we know his identity".

Once that happens, she added: "The partisan machines will get cranked up and he will read about this person he doesn't recognise." She warned his entire life will be raked over, even down to "what kind of salad dressing" he uses.