Transport secretary Justine Greening accorded priority status to the scheme following an application from Mayor of London Boris Johnson.
This designation increases prospect of new Silvertown tunnel being open for traffic in 2021.
It means that the project will be subject to the process for a development consent order by the Secretary of State but could ultimately reduce the overall timescale required to secure all necessary approvals for the project.
The Silvertown tunnel would relieve congestion on the Blackwall Tunnel and, to a lesser extent, on the M25’s Dartford Crossing.
Transport for London (TfL) will now take forward design work and undertake further consultation later this year to prepare for the formal development consent order process.