By John King
For a few moments Wednesday, 10 Downing Street found itself playing host to two very different voices from the political debate across the pond.
Former New York Mayor Rudy Guiliani was there for a courtesy call on Prime Minister Gordon Brown.
The meeting was a tad late because Brown ran overtime with a meeting of his political cabinet. On hand for that session: US based pollster Stanley Greenberg, a Democrat who was an architect of Bill Clinton's 1992 presidential victory and also a leading voice now in his party's views on health care and economic policy.
Greenberg for years also has worked for Britain's Labor Party, and among recently installed PM Brown's pressing issues is deciding when to call national elections.
Worry not: there was neither debate nor detente between the Democratic strategist and Republican hopeful.
Greenberg told CNN as he left 10 Downing that he and Guiliani passed by each other in the hallway as Brown ended his political meeting and moved on to his sit down with Guiliani.