Meanwhile other people have aspirations for using the Sutton Loop
Quote

http://www.yourlocalguardian.co.uk/n...nto_sutton.php

Tube and tram could extend into Sutton
Plans to 'stretch' the Northern Line and build a new station in Merton
have been included in a series of ambitious transport proposals
compiled by the leaders of south London councils.
The line would use the current sidings running through the south of
the borough and is part of a list of transport priorities presented to
Ken Livingstone and Boris Johnson in the run up to the London Mayoral
elections.
The Tramlink has also been earmarked for an extension as part of the
proposals with Wimbledon being connected to Sutton.
"There's a real chance that these ideas will be taken seriously," said
Merton Council leader David Williams.
"Yes, it's aspirational but if you don't dare to dream it will never
happen."
Both Livingstone and Johnson have agreed to consider the plans after
recent visits to the borough where they were presented with the
proposals.
Mr Williams added: "It makes sense to do this because it won't require
tunnelling and while it may well cost tens of millions of pounds, it
will increase the connectivity of the area enormously by running the
Northern Line as far as St Helier.
"And the extension of the Tramlink to Sutton will make a huge
difference to the orbital network, improving accessibility and taking
cars off the road. It will also open up more job opportunities."
According to the leader of Merton Council, Greater London Authorities
statistics also suggest there is potential for economic growth in the
area but it is being "suffocated" by poor transport links.
7:21pm Wednesday 2nd April 2008
unquote

From looking at the map it seems an obvious link - but if so why has
this not been done before. IIRC the southern end of the Northern line
gets quite congested - Is this because the stations are too small, the
train frequency too low or the peak hour passenger demand too great.