A row over the success or failure of a pilot project teaming up private rail firms and rail infrastructure has intensified. Earlier today Bob Crow - the leader of the National Union of Rail, Maritime and Transport Workers (RMT) - criticised the scheme's performance - saying standards had slipped.
However the South West Trains-Network Rail Alliance, whose collaboration sparked the comments has responded to the RMT's claims, saying it was wrong to compare a period of challenging bad weather last year with one of the best periods ever this year - including the Olympic Games in London.
"In his rush to try to make an opportunistic political point, Bob Crow has chosen to not look at the wider picture and has been selective in his choice of evidence to support his claims. The fact is that in the first period of the Alliance, which the RMT are using as a comparison, our services were heavily impacted by severe weather, something completely out of our control, which cannot possibly be compared against one of the best periods ever during April 2011.
"The reality is that over the first five months of the Alliance, we have maintained our high level of performance on one of Europe's busiest commuter network and the most recent figures show that last month we achieved the highest level of punctuality in two years at 95.8%.
"This was achieved against a backdrop of some major challenges, including flooding on the network and the increased numbers of passengers travelling on our network during the London 2012 Games.
"Our frontline staff, including RMT members, have helped our trains continue to be amongst the most punctual in the country. But we are determined to keep on improving. The more collaborative approach under the Alliance will help us to deliver an even better service to passengers and a more efficient railway for taxpayers."