The operator became the first to be nationalised under the new Labour Government in May.
But a number of the new trains are still sitting stationary at the Clapham depot.
Lib Dem MP, Paul Kohler claims the cost to the taxpayer of keeping them there is £5 million monthly.
Liberal Democrat Transport Spokesperson and MP for Wimbledon, Paul Kohler said:
“It is simply unacceptable that taxpayers are footing a monthly bill in excess of £5.5m for trains gathering dust in a depot, whilst commuters in Wimbledon and the South West still have to deal with overcrowded trains.”
“Ministers must come clean on why the Arterio fleet is still not fully in service, and when this costly farce will finally end.”
The Department for Transport has not released details of the cost of keeping the trains unused.



