THE pace of the Australian attack was ferocious. ''Thieving Poms!'' was the first scorching delivery, followed by ''Traitor!'' and ''Rat!''. England hit back gamely: ''Whingeing Aussies!'', ''Ozhypocrites!''. The sport of gentlemen put to another Test. But even as the row escalated over the charge that England had poached the Australian cricketer Martin McCague for the Third Test, British athletics was garlanding an American female runner for salvaging Britain's national pride. Unlike McCague, the fast bowler who has spent 22 of his 24 years in Australia, Suzanne Rigg was born in Iowa and got a British passport thanks to her marriage to her British coach. Rigg, 28, stepped in to replace Liz McColgan, Britain's injured top long-distance runner, to win fourth place in the recent European Cup 10,000 metres in Rome. Australian anger was fuelled by the knowledge that McCague had been trained at the exclusive Australian Cricket Academy, prompting his uncle, Neil McCague, to call him ''a traitor'' and Allan Border, the Australian captain, to claim England had ''forsaken national pride''. In less measured terms, the Daily Telegraph Mirror in Sydney dubbed McCague ''the rat who joined the sinking ship''. Rigg, however, attributes her development as a runner to the British athletics system. She moved to Liverpool in 1988 and it was only after a decent showing last year that she was seized with an urgent desire to obtain a British passport. She raised a few eyebrows by admitting she accomplished this in six months instead of five years after the intervention of an MP. But the cross-fertilisation does not stop there. England's cricket line-up is bolstered by Andrew Caddick, a New Zealander who waited four years to satisfy residence qualifications, and Robin Smith, whose South African tones closely match those of Allan Lamb and the dropped player Graeme Hick (Zimbabwe). Nor has Britain restricted its imports to the former colonies. England's top table-tennis player is Chen Xin-hua, 33, who played for the Chinese national team before qualifying to represent England in 1990. China vetoed his participation in last year's Barcelona Olympic Games. The best-known face in English basketball is that of Alton Byrd, an American who arrived in Britain in 1979 after a glittering career on the American college circuit. By 1984 he had a British passport, but three years later he was surprised to find himself registered as a Scottish player: he had posted his application from Edinburgh. It was not until 1990 that he was welcomed to English colours. Joining the British tennis squad seems an unlikely aspiration for foreigners, but the Cape Town doubles player Neil Broad, 24, had no qualms about aligning himself with the land of the losers when South Africa was banned. Producing a British father and passport, he had affirmed his English heritage: ''My dad has always brought me up to think like that.'' Ranked 10th in Britain, he did not qualify for Wimbledon this year. A similar refrain came from Monique Javer, 25, from San Francisco, who was dubbed ''the Zola Budd of British tennis'' when she was cleared to play for Britain in 1988. Javer, too, had a British-born parent. ''Mom always taught us to be English,'' she said in a Californian drawl. Ranked second in Britain, she was beaten in the second round at Wimbledon. But the latest clamour proved one thing: let he who is without foreign-born sportsmen hurl the first bouncer. Australia, which is reportedly challenging the cricket eligibility rules, is on a distinctly sticky wicket. Its most flagrant mercenary was the South African cricketer Kepler Wessels, who became an Australian to play in the national side before reverting when the anti-apartheid ban was lifted. Other examples abound in the Australian sporting pantheon. They include top surfer Wendy Botha (South Africa), Olympic basketballer Leroy Loggins (United States), World Cup rugby hero Willie Ofahengaue (Tonga), boxing champion Johnny Famechon (France), swimmer John Konrads (Latvia), footballer Jim Stynes (Ireland), tennis player Wally Masur, national football coach Bobby Fulton, and football captain Paul Wade (all Britain). But the Republic of Ireland football team takes the biscuit. Among the players, the accents of Liverpool, Scotland and London's East End mingle with the Geordie strains of the manager, Jack Charlton, and Devonian consonants of his lieutenant, Maurice Setters. During the past seven years the two have trawled for British players with an Irish grandparent. One story, perhaps apocryphal, is symbolic of the bewildering mobility of sportsmen and women across national frontiers. Andy Townsend, Ireland's cockney captain, was about to play an international against a team from Eastern Europe. ''I don't think muchof their national anthem,'' he remarked as the music struck up. ''Don't be daft. That's ours,'' came the retort. The Sunday Times