A new station would be created at Transport Avenue, Brentford, close to the A4 Great West Road and GlaxoSmithKline and Sky 's headquarters, under the proposals.
It would be connected with Southall via an existing freight line, with three trains an hour running between the two stations.
The proposals were first mooted by Hounslow Council in 2014 when it unveiled plans to create nearly 30,000 jobs and 1,600 new homes along the stretch of the A4 known as the Golden Mile .
It had hoped the new link would open in time for the launch of Crossrail in 2019 but it now says it could be up and running the following year "in an ideal world".
Should the new line open, the long-term plan is to connect the new Transport Avenue station with Brentford train station to the south, though this is likely to be many years further off.
Hounslow High Speed 2 connection 'very high' value for money
The council also wants to connect Hounslow train station with the proposed new High Speed 2 hub at Old Oak Common, in Shepherd's Bush - or if that station is not built, with Willesden Junction - though that would not happen before 2026.
A report commissioned by the council suggests the Southall-Transport Avenue link and the Hounslow-Old Oak Common line would together cost around £40.5m to build.
The report, produced by WSP|Parsons Brinckerhoff, suggests the Southall-Transport Avenue link would be "high" value, while the Old Oak common connection represents "very high" value.
A council spokesman said it was now trying to persuade Transport for London (TfL) to fund further feasibility studies on the new connections, which would be significantly more expensive than the initial cost analysis carried out for the council.
'No shortage of backers willing to invest'
Should these support the case, he said the council could fund the work itself by borrowing the money and paying it off using the increased business rates the links would generate.
"The value-for-money analysis has really supported our case with TfL, and I don't think there would be any shortage of backers willing to invest to create the links," said a council spokesman.
"We had been working towards bringing in a passenger service to Southall by 2019 but that's not looking feasible and we're now looking at 2020 in an ideal world."
Hounslow Council recently returned from the global property conference MIPIM, in Cannes, where it said there had been significant interest from potential investors in development opportunities along the Golden Mile .