Among the options is a lower initial operating speed on the line.
HS2 has been designed to allow trains to run at up to 360km/h (224mph). Department for Transport sources point out that this is faster than any other conventional railway in the world.
Most high speed trains in this country run at up to 200km/h (125mph), while those on the Channel Tunnel Rail Link (HS1) operate at up to 300km/h.
This means HS2 trains could not be tested at their intended operating speeds until a bespoke test track, or the railway itself is complete, something DfT sources claim would delay completion of the project by several years and cost billions of pounds.
The alternative, they say, would be to send trains to China to be tested on existing tracks there.
The government has been highly critical of decisions taken by previous administrations. Last year, the Transport Secretary described the scheme as “an appalling mess”.
The Conservatives have been approached for comment.