Network Rail is failing to deal with snowfall and heavy rain on London and south east lines, according to an independent report released today.
The Office of Rail Regulation (ORR) criticised train punctuality in London as falling ‘even lower than thought previously’, between October 14 last year and January 5.
It also said that across the UK passengers had suffered from some substantial over-runs of engineering works over Christmas due to poor management and "several instances of basic operational planning mistakes causing delays."
An ORR spokesman said: "We have concerns about Network Rail’s resilience in dealing with recent weather conditions and are raising this urgently.
"Although it did much to recover weather-related delays, there were other factors affecting performance such as some significant engineering overruns.
"We want a full account from Network Rail about how it will improve its performance in future"
London lines are predicted to fall one per cent short of their punctuality target of 93 per cent, by the end of March 2014.
An ORR spokesman said: “In December, we re-affirmed our expectation that Network Rail will do everything reasonably practicable to deliver 93% PPM.
" We are therefore disappointed that it now expects that LSE London and South East will end 1.1 percent below target."
Network Rail has missed its UK targets for punctuality by 2 per cent.
It is now at 88 per cent, which is worse than it was this time last year.
Cancellations and significant lateness have also increased across the London lines.
Despite this, overall satisfaction on the lines has reached an all time high of 85 per cent, with 85 per cent of passengers very or fairly satisfied overall with London and South East operators.