Davis, head of Paul Davis & Partners and president of the Association of Consultant Architects, said visa regulations must be clarified to allow practices to take on the best young architects from around the world if the government wants them to bring in revenue by taking on work abroad.
West London-based Davis said there was a fundamental contradiction at the heart of government, which sees leading practitioners being taken to all corners of the earth on trade missions - but not being able
Davis' comments come in the light of his practice losing two Russian architects because the Home Office would not extend their one-year visas.
He said this had undermined his chances of expanding his firm's workload in Russia's vast construction market.
'London is very nearly a world leader in architecture and construction, but it is not quite there,' he told the AJ.
'If it wants to be there, then architects must be allowed to employ the best staff from around the world.
'We could become a leader, but this is letting us down.
'My practice has had a lot of interest from St Petersburg since we first won a masterplan project when I was over there on a UK trade mission.
'But since we lost our two wonderful Russian architects it has become very difficult to take this work on.
'It is all well and good the government taking us out there to build relationships, but then this happens,' he added.
A spokesman for UK Trade and Investment, a DTI agency which organises trade missions, said: '[Davis] has chosen to bring people here rather than opening an office over there.
'We helped him to get the work, it is up to him how he takes it forward.'
A Home Office spokesman said: '[The visa situation] would depend on what kind of programme these people came to the UK with.
'We do offer a 'highly skilled migratory programme', which changed from a one-year visa to a two-year visa, earlier this year, and there is a chance to extend this further.'