Ireland prop Andrew Porter's scrummaging technique "may need some referee intervention" in Saturday's match, says England coach Eddie Jones.

The Australian has also drawn attention to the number of players who qualify for Ireland on residency grounds.

"Someone called them the United Nations," he added.

Five of Ireland's starting XV for the Autumn Nations Cup game - Bundee Aki, James Lowe, Jamison Gibson-Park, CJ Stander and Quinn Roux - originate from New Zealand or South Africa and are eligible after living for three successive years in Ireland.

Former internationals such as Luke Fitzgerald and Tony Ward have criticised Ireland's use of such players in the past.

"Andy Farrell, Mike Catt and Simon Easterby are just selecting the team they are allowed under the regulations," added Jones of the Ireland coaching team.

"I can understand how Irish people would be upset about Irish-born players missing out, but they are the laws and regulations of international rugby. They are just sticking by the regulations."

World Rugby is increasing the qualifying period to five years for players capped after the end of 2021.

Porter, touted by Ireland scrum coach John Fogarty as a "very, very smart player", disrupted the Wales front row at the set-piece during last Friday's Autumn Nations Cup opener.

Wayne Pivac's side incredibly won only one of five scrums on their own put-in.

Jones suggested the key man in the scrum contest at Twickenham may be French referee Pascal Gauzere.

"I'll leave that up to the referee," he said when asked for specifics about Porter's play.

"The scrum contest is always challenging against Ireland. We've got a referee who generally doesn't reward dominant scrums so it'll be interesting to see how he looks at that area.

"We'll need to be adaptable to his calls on it - it's no use scrummaging if you can't get a result out of it."