Portugal boss Scolari had been offered the job of succeeding Sven-Goran Eriksson but the Brazilian delivered a bombshell when he made his shock statement from Germany, where he was examining Portugal’s World Cup facilities.

He said he was unwilling to deal with the pressure of journalists camped outside his house.

McClaren had been favourite for the job at one stage before Scolari’s late emergence.

The Brazilian’s announcement swung it back in the Middlesbrough chief’s favour but revelations in The Sun newspaper about an affair with a secretary last year will not have helped his cause.

“I don’t know why this has come out at this time but I want to clear it up,” he said in a statement carried by the newspaper.

“I was separated from my wife a year ago and had a three-month affair. It ended at the end of August last year and I went back to my wife in September.

“The rumours of the affair began circulating recently and I don’t know how or who was responsible or why this has come out at this time. I want to clear this up.

“I feel this is a private matter but in view of speculation about myself and the England job, I felt I had to clarify the situation.

“Lots of people up here were aware of this but it was something that happened a while ago, while my wife and I were not together, and it’s now in the past.”

“I felt I should be honest and open. But I am puzzled as to why after all this time these rumours are suddenly surrounding me. I now want to draw a line under this and concentrate on my family and Middlesbrough.”

One of several scandals involving Eriksson surrounded the Swede’s affair with FA secretary Faria Alam before a meeting with an undercover Sunday newspaper reporter effectively sounded the death knell to his tenure as England boss.