WHEN Washington was custom-designed as the federal capital back in the late 1700s, architect Pierre L'Enfant must already have had the need to accommodate the lobbyists in the back of his mind. With its sweeping avenues supporting a network of majestic federal buildings, framed at either end by the White House and the Capitol, the ease of movement in the city centre allows a cause, an idea, or a campaign to circulate through town in no time at all. But seasoned as they may be, Washington's congressmen and government officials can hardly have been prepared for the current lobbying assault from Hong Kong. If this is spring, it must be time for the renewal of Most Favoured Nation (MFN) trading status for China, and if that is the case, the movers and shakers who matter will have to take their phones off the hook if they want to escape the barrage from Hong Kong. Two months ago, the charge was led by a visiting delegation from the American Chamber of Commerce, followed last month by a visit from Secretary for Trade and Industry Brian Chau Tak-hay; then came last week's energetic delegation led by Paul Cheng Ming-fun of the General Chamber of Commerce. And now - although who can say if it is the last sally of the season - a volley from Hong Kong's most powerful weapon so far: Chief Secretary Anson Chan Fang On-sang. Mrs Chan arrived this morning at her base in the fashionable Four Seasons hotel, and went almost immediately to dinner at the elegant, oak-panelled Georgetown Club. It was there, at an establishment which appropriately had long-standing reciprocal links with the Hong Kong Club, that Mrs Chan and the territory's man in Washington, Barrie Wiggham, were due to pore over the strategy for a whole week's worth of high-powered flesh pressing. Even now, the itinerary is rewriting itself as regularly as congressional staffers forget to return phone calls. For example, it is still unclear whether Mrs Chan will be able to secure a meeting with Vice-President Al Gore, and Hong Kong office staff have also been fretting about whether the death of former president Richard Nixon might rip a hole in the schedule, with VIPs lined up to see the Chief Secretary suddenly called away for a funeral or other respects-paying activities. One way or the other, sleepless nights by staff at the territory's Washington and New York offices will no doubt ensure Mrs Chan gets to see everyone she needs, and secures the media interviews she wants. And the level of VIPs who have agreed to see her - from Treasury Secretary Lloyd Bentsen, through to Acting Secretary of State Strobe Talbott and National Economic Adviser Robert Rubin, not to mention key congressional leaders - leaves no doubt as to the level of respect she is being paid. What exactly does the Chief Secretary expect to achieve from the visit? The question is to some extent rhetorical, and if Emily Lau Wai-hing and other cost-conscious legislators, perhaps unfairly, expect an answer that looks like a checklist of achievements, that does not mean the question will not be asked. Mrs Chan is, after all, not alone, but is accompanied by a medium-sized entourage including an aide, press assistant Kerry McGlynn, and Director General of Trade Tony Miller. One possible fear is that some of the lawmakers and officials seeing Mrs Chan, notably Assistant Secretary of State Winston Lord, will already have met all previous delegations, not to mention their routine contacts with Mr Wiggham, the permanent fixture here. It may be possible, therefore, for a certain Hong Kong fatigue to set in. Another question is to what extent is Washington willing to consider the future of Hong Kong in this year's MFN debate? PRESIDENT Bill Clinton and his advisers are already aware from last year's struggle how badly the territory and Taiwan will be hit by revocation, and going through the President's mind now are matters that are far more political and strategic: how to maintain political and trade links with China while not offending the human rights lobby; how to renew MFN without sparking a congressional revolt; and whether sanctions will kill America's chances of getting China's co-operation on arms proliferation and North Korea. Mr Wiggham, the target of recent attacks by Ms Lau as to the worth of his Washington posting, is aggressively defending his role and that of visits such as Mrs Chan's. In an interview, he pointed out that MFN was only part of the Chief Secretary's mission. Her other aims included promoting trade and tourism in the territory. He said: ''It's true Hong Kong is not centre stage, and you could ask the question about how relevant it is. My view is that the potential damage [from loss of MFN] to Hong Kong is . . . greater than it was last year, and the need to make sure people understand this is greater than ever. ''We owe it to ourselves to make sure Hong Kong stays known. It would be irresponsible if we let the Hong Kong case go by default,'' Mr Wiggham said. ''It must be that there are some individuals in the administration who are wavering [on MFN] and in that situation it may be that the Hong Kong argument will carry some weight.'' Mr Cheng, who believes President Clinton will engineer a way out of the tight corner in negotiations with China and renew MFN, puts it more bluntly. ''Hong Kong can be useful in that Clinton needs every item he can get with which to package his decision,'' he said. Mrs Chan is entering the MFN debate at a time when so many cards are being partially shown by the administration, it is difficult to know whether they are hiding a losing hand or a royal flush. Whether to separate trade with China from human rights is only part of the problem for Mr Clinton; while the State Department urges him to stand firm on the human rights issue, other officials from the financial camp - most notably Mr Bentsen and Mr Rubin - are reportedly urging him to renew MFN at all costs. And if, as is now being touted, a compromise set of limited sanctions may be applied, what are the options? United States officials have privately stepped on the idea of MFN being applied only to state-run industry, and both Mr Wiggham and Mr Cheng believe it to be unworkable. Should action be more selectively taken, as Senator Max Baucus urged last week? Or will the most cosmetic proposal of all, a joint US-China Human Rights Commission, be enough to pacify Congress? In this climate, the Chief Secretary may find it pragmatic to abandon Hong Kong's traditional all-or-nothing stance that only unconditional renewal will do; in her meetings with key figures such as Mr Lord and Mr Rubin, she has the chance to mull over the options and push the officials towards the weakest ones. Mr Cheng conceded last week that he did not think the President would be able to separate fully MFN and human rights this year, and Mrs Chan could play a role in cutting China's - and Hong Kong's - losses to a minimum. Her itinerary also shows a useful bias towards meetings with thinkers as well as policy-makers - an initiative started by Mr Wiggham during his regular rounds. He believes think-tanks and academics are far more respected and listened to by the US Government than in comparable Western societies such as Britain. ''It's an important constituency because in the US the academic world has considerable influence on the administration, and some of them even go through the revolving door into the administration. They are not living in ivory towers,'' Mr Wiggham said. The territory's efforts are reaping results - many in Washington appear to think a lot of Hong Kong. Former Beijing ambassador James Lilley, now with the American Enterprise Institute, was recently effusive in his praise of an MFN fact-sheet being circulated around the corridors of power by the local Hong Kong office. And Robert Kapp, the new president of the US-China Business Council, called the territory's lobbying strength ''awesome''. And even if there is a certain Hong Kong fatigue factor in some quarters, the territory is quietly - quietly because you cannot really get away with saying such politically incorrect stuff in America - relying on two positive publicity factors: the fact that Anson Chan is the first ethnic Chinese in her position, representing to American eyes the end of a colonial era; and the fact she is the first woman to break so forcefully through the glass ceiling. Despite news clashes with South Africa's elections and the crisis in Bosnia, the chances are Hong Kong will not have figured so strongly in Washington's consciousness since Governor Chris Patten's visit last year. And with MFN in the balance like never before, there probably is still time for Mrs Chan to add an important voice.