Tory Chief Whip Andrew Mitchell's outburst at Downing Street police officers has been "very damaging" for the party, a senior minister has said.
Defence Secretary Philip Hammond said Mr Mitchell's conduct had been "inexcusable" and the party needed to be able to draw a line under the matter.
"Every time any individual slips up, steps out of line, does something they shouldn't have done, commits an indiscretion, and they are a member of a party or an organisation, of course that is bound to reflect on that organisation," he told the BBC1 Sunday Politics programme.
"We have to accept that, it is very unfortunate. Nobody is defending Andrew Mitchell's conduct but a line now has to be drawn under it. This has been a very damaging affair."
Mr Mitchell was forced to apologise after police said he swore repeatedly at the officers and called them "plebs" after they refused to allow him to cycle through the main gates of Downing Street.
Although he disputes the word attributed to him, he is staying away from the Conservative Party conference opening in Birmingham after saying his presence would be a "distraction".