The rail company due to take over most services in Sussex still has a worse punctuality record than current operator Connex.
Figures released by the Strategic Rail Authority today revealed less than seven out of ten trains operated by Thameslink arrived on time in February 2001.
Punctuality during peak times dropped from 70 per cent to 66.3 per cent with an improvement on day services from 65.3 per cent to 67.3 per cent.
Their performance is the third worst in the South-East and London from February 4 to March 3.
Connex South Central's scores during the same period were 67.3 per cent at peak times and 72.2 per cent for day services.
Connex lost the South Central franchise to Govia, which operates Thameslink trains between Brighton and Bedford.
The current franchise expires in May 2003 but negotiations are currently being held with the rail authorities to hand control to Govia early.
Thameslink dramatically improved its peak-time record from 45.6 to 70 per cent in January.
The SRA said the company was one of four which could partly blame their poor performance in February on emergency speed restrictions.
A Thameslink spokesman said: "Restrictions post the Hatfield crash are still in place and the routes we use are terribly congested. We are working to bring our punctuality back up."
A Connex spokesman said the figures showed a trend of improvement in its services since the chaos caused by the crash last October.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article