There has been a longstanding dispute between unions and National Express regarding its US operations.  The Unions allege that the company's US subsidiary engages in systematic anti-union behaviour.  The company disputes this.  See previous coverage:

• 80 UK MPs write letter to National Express over alleged "systematic" denial of workers' freedom of association at US subsidiaries

• Union pension funds urge other shareholders to vote against annual report & accounts at National Express annual meeting on 9 May over labour rights concerns at US subsidiaries

• New report "highlights serious flaws in National Express Group’s human rights policy", say unions

The report from The Trade Union Group (made up of UK MPs) is based on a fact finding trip to South Carolina and Tennessee by Ian Lavery MP and Jim Sheridan MP.  You can access the report and National Express' response to it below.