Labour is to run much of its election campaign from offices next door to the new Tory HQ in central London.
Labour is taking more office space next to the Tories
A party spokesman said Labour was taking additional space for a media centre and extra accommodation for staff and senior figures.
The Tories moved from their old Conservative Central Office base in Smith Square earlier this year.
Now Labour will join them in taking offices on Victoria Street but keep its nearby Old Queen Street headquarters.
The move is to allow space for an extended staff during the run-up to an election widely predicted for May next year.
Labour's previous headquarters in Millbank Tower became synonymous with the party's slick, modern campaigning machine that finally won it power after 18 years in opposition and then secured an historic second full term for the party.
The decision to move the Tories came shortly after Michael Howard was made leader last year.
As part of their gearing up for an election campaign the Tories' new base is now known as Conservative Campaign Headquarters.