Hugh William Mackay, The 14th Lord Reay, who has died aged 75, was the most cosmopolitan of aristocrats. Hereditary chief of the Clan Mackay, he also held an old Scottish title; was an elected member of the House of Lords; and held a barony, and an estate, in the Netherlands.

Immaculately turned out (to the point where one society columnist termed him “foppish”), Reay was nevertheless a serious political figure. First a Liberal and later a Conservative, he sat for six years in the European Parliament and was briefly a minister in the Thatcher/Major government.

Reay’s Scottish peerage, which dated from 1628, made him a Lord of Parliament, the equivalent of a baron south of the Border, and he was one of only two to sit in the Lords after most hereditaries were ousted in 1999. (Lady Saltoun was the other.) He was also Baronet of Farm, a Nova Scotia title bestowed by James I and VI on a forebear in 1627.

His father, through the distinguished Dutch branch of the Mackay family, succeeded to the barony of Ophemert and Zennewijnen, created in 1822 by King William I of the Netherlands. With the title came the picturesque 16th-century Ophemert Castle, which is still in the family.

Hugh William Mackay was born on July 19 1937, the only son of Aeneas Alexander Mackay, the 13th Lord Reay, and the former Charlotte Younger. From Eton the then Master of Reay went on to Christ Church, where he was rated one of the best-dressed men at Oxford.

He was living in Holland when, in 1963, his father died and he succeeded to his titles , becoming a representative Scottish peer. Reay initially sat as a cross-bencher, but after playing a prominent role in putting through the Bill that abolished capital punishment he joined the Liberals in 1966.

In 1971 he returned to the cross-benches, saying the Liberals could “no longer claim to be a national party”, and the following year he joined the Conservatives.

When Britain joined the Common Market at the start of 1973, Reay was one of eight peers nominated to serve in the European Parliament . He immediately pitched into Francois-Xavier Ortoli, president of the Commission, over the siting of the assembly in Brussels, Strasbourg and Luxembourg rather than at one location. Before long he was vice-chairman of the Conservative group.

When the first elections to the European Parliament were held in 1979, Reay was nominated instead to the Council of Europe, serving until 1986. But he concentrated increasingly on the Lords, taking a hawkish line on defence.

Margaret Thatcher appreciated this, and in 1989 appointed him a Lord-in-Waiting, or junior whip. Reay spent much of his time at airports seeing off members of the Royal family and visiting heads of state, but also spoke for the government on a range of issues.

He upset campaigners against Chinese rule in Tibet by stressing that Britain recognised the Dalai Lama as a spiritual leader, sidestepping his political status. On behalf of the Department of the Environment he had to oppose pressure for the phasing out of CFC gases before, in 1991, he moved to the Department of Trade and Industry, which he found quicker to embrace “green policies”. One of his first announcements was a package of grants for recycling. Reay also promoted European cooperation on R&D, and urged British film makers to stop expecting subsidies and make films the public wanted to see.

Leaving the DTI after just under a year, he joined the Select Committee on the European Communities, serving until 1999 and chairing its food and agriculture subcommittee.

Lord Reay married, in 1964, Annabel Therese Fraser (now Tessa Keswick), younger daughter of the 17th Lord Lovat; they had two sons and a daughter. They divorced in 1978, and in 1980 he married Victoria Warrender, daughter of the 1st Lord Bruntisfield; they had two daughters. His elder son, Aeneas Simon Mackay, Master of Reay, born in 1965, succeeds to the titles.

The 14th Lord Reay, born July 19 1937, died May 10 2015

Photo: Chief and his Lady in Edinburgh 2009 at The Gathering