The Government is facing the latest legal challenge to its £32 billion high speed rail link between London and Birmingham.
Opposition group HS2 Action Alliance has contacted the European Commission over concerns about the environmental impact of the line.
The group has also written to Transport Secretary Justine Greening asking her to abandon the scheme and warning it could challenge her decision through judicial review.
A separate letter of complaint regarding the UK Government’s “non-compliance with the SEA directive” was also sent to the EC, “inviting the commission to investigate the actions of the UK Government on this matter”.
Last week, a group of 18 local authorities called ‘51m’, said they had written to the Ms Greening threatening a judicial review unless the project is rescinded.
The group, which is called 51m because £51m is how much they think HS2 will cost every parliamentary constituency, includes a number of Warwickshire and Staffordshire councils.
Journey times to London will be sliced from one hour 20 minutes to just 49 minutes if the high-speed rail link goes ahead.
Members of Kenilworth-based Stop HS2 Action group said they were “pleased” by the stance taken by 51m.
Joe Rukin, of Stop HS2 Action, said: “HS2 is a complete waste of money. The plans haven’t been thought through properly and will not deliver what has been promised.
“People say this is going to be good for the West Midlands, but it won’t be.
"It may help the Eastside development in Birmingham, you might see commuter villages, but besides that, more commuter villages will spring up in the Meriden Gap between Birmingham and Coventry.
“The consultation has been completely flawed.”
Journey times from Birmingham to London will be sliced from one hour 20 minutes to just 49 minutes under the plans.