More than a decade after it was initially proposed, serious works on Melbourne's Metro Tunnel project begin from Monday – including the first tree removals and two major street closures.

The works will mark the beginning of lengthy road works and traffic delays for the St Kilda Road precinct that will last years.

But despite the first of hundreds of trees going, and gas and sewer pipeline relocations starting, the design and exact location of a new underground station at Domain is yet to be finalised.

From Monday, Franklin and A'Beckett streets will partly close, for five years for tunnelling work.