Zachares, now a top staffer on the House Transportation and Infrastructure Committee, once served as a labor and immigration official in the Commonwealth of the Northern Mariana Islands, a U.S. territory. Abramoff represented the territory and its apparel manufacturers at the time.
Brooks is chief of staff to Rep. Jim McCrery (R-La.), who was then fighting attempts by the Jena Band of Choctaw Indians to open a casino in his district.
The lobbyist also opposed the proposed gaming facility because it would have competed with a client's casino.
Neither Brooks nor Zachares responded to questions from The Times.
The National Center, in acknowledging its sponsorship of DeLay's 2000 trip, made no mention of golfing in Scotland.
Its statement noted the trip involved "significant policy meetings" -- including a visit with former Prime Minister Margaret Thatcher. "We were then and remain honored that they chose to accept our invitation," the statement reads., It calls the trip "consistent with our mission as an educational foundation."
The trip for DeLay and his entourage cost about $70,000, records show.
DeLay, known as "the Hammer" when he became Republican whip a decade ago, also was a guest of the center in 1997 for a trip to Russia.
The National Journal reported in February that Abramoff sought reimbursement from his then-law firm for $13,318 in hotel bills incurred on the 2000 trip, including $4,285 for DeLay and his wife to stay at a London hotel.
Payment of DeLay's hotel bill by lobbyist Abramoff would be prohibited by House ethics rules.
Abramoff bragged of setting up the Scottish golf trip for his friend DeLay, according to Senate testimony and e-mails.
In a June 7, 2002, e-mail to Tigua consultant Schwartz, Abramoff wrote of the upcoming Ney golf junket, saying it "will be quite expensive (We did this for another member -- you know who) two years ago."
Abramoff identified "you know who" as Tom DeLay, Schwartz testified.
DeLay bristled when asked last week about the Britain trip, saying he reported it properly. He brushed aside questions about the lobbyist, saying that "Jack Abramoff is not the only person I talk to in Washington, D.C. I have a lot of relationships, hundreds of relationships."
Records show their relationship has benefited Abramoff over the years.
In one case, DeLay helped stop a Republican proposal to tax Indian casino proceeds. Abramoff's client at the time was among the leading opponents of that tax.
Since the golf trip, DeLay has continued to help Abramoff's clients. In 2003, he joined the House speaker and other Republican leaders signing a letter to Interior Secretary Gale A. Norton. The group opposed a proposed casino in Louisiana that would have competed with another club run by one of Abramoff's biggest clients.
Times researcher Mark Madden contributed to this report.