LONDON (AP) — Britain's Conservative Party says one of its lawmakers will face an investigation after he ejected a climate protester seeking to interrupt a speech by the nation's Treasury chief at a gala dinner.

Party chair Brandon Lewis says that lawmaker Mark Field referred himself to an investigation by the Cabinet Office after he was filmed grabbing the woman at the Mansion House event on Thursday.

Lewis told ITV it was "very hard to defend" the footage, but says the investigation will look into the "full details of what happened."

Fellow Conservative Peter Bottomley defended Field, saying he "did what any sensible person would have done" in ejecting the protester.

Bottomley told the BBC the demonstrator could have been "carrying a collapsible truncheon."

Treasury chief Philip Hammond continued his speech and defended the government record on climate change.