The US Open clashes with parental duties for Lawrie

Seven others, including England's James Hepworth, Simon Wakefield and Robert Rock and Irishman Peter Lawrie, have also opted out of the 36-hole event.

It leaves just 65 players competing for nine qualifying places at Walton Heath.

Lawrie, whose five-year exemption for winning the 1999 Open ran out in 2005, said his wife Marion will be in hospital at the time of the US Open.

I'm not prepared to sacrifice the other tournaments that are on Bradley Dredge

The likes of Darren Clarke and Paul McGinley lead the big-name entries in a diminishing field, with American Notah Begay, Spaniard Alvaro Quiros and Indian Jyoti Randhawa also pulling out.

Welshman Bradley Dredge also decided against entering the tournament, explaining: "I just don't want to do it and luckily I don't have to answer to anybody.

"I don't do the Open qualifying or the US Open qualifying. I'm not prepared to sacrifice the other tournaments that are on."

Meanwhile, Spain's Pablo Martin, who on 1 April became the first amateur to win a European Tour event, will make his professional debut in the US version of qualifying.

The 20-year-old, who beat Raphael Jacquelin by one at the Portuguese Open, will be among 144 players in Columbus, Ohio, competing for 24 places in the starting line-up at Oakmont the following week.

Also in the field are former Open champions Tom Lehman, Mark O'Meara and Mark Calcavecchia, ex-US Open winner Steve Jones, 1993 US PGA champion Paul Azinger and a host of US Tour winners.

The 2007 US Open will take place at Oakmont Country Club in Pennsylvania from 14-17 June.