CONCERNS have been raised about a plan to build an underground rail link in Southampton.

Transport for the South East unveiled the ambitious proposal to link Southampton Central with the Netley line back in the summer.

It was part of a wider £45bn package of transport improvements - all of which are subject to further consultation and need to be funded.

But now Southampton City Council has outlined its concerns over risks to the environment, the cost and whether or not it is feasible.

READ MORE: Plans for new underground link between Southampton and Netley railway lines

In its response to a consultation on the wider plans, the city council said: "As highlighted throughout the development of the SIP (Strategic Investment Plan), we have concerns about the proposed rail tunnel under the River Itchen due to potential challenges related to cost, deliverability and environmental impact. It should also be noted that a tunnelling option is not currently considered within our LTP (Local Transport Plan) or Local Plan."

The tunnel was proposed in a bid to cut the rail journey times between Southampton and Portsmouth.

One campaigner previously told the Echo the plan was 'very ambitious' and he was 'flabbergasted'.

The city council's consultation response added: "Whilst proposed investment in rail infrastructure (is) based largely on the Solent Rail Study and contributes to the above benefits, we have concerns about the potential negative impacts of the proposed Enhanced Rail package for South Hampshire, specifically the proposed tunnelling options under the River Itchen.

"This project is complex and contains a number of risks and is not a current policy option locally.

"The (report) illustrates the likely negative impacts of the proposed tunnelling options on the natural and built environment, which are vital assets to the city.

"Despite challenges related to cost, deliverability and the environmental impact of the Enhanced Rail package, we also acknowledge its potential benefits in supporting our aspirations for metro-levels of rail service and improved connectivity across the Solent area.

"If this scheme is funded and taken forward in the future, it will be subject to statutory assessments as well as planning consent and public consultation."

The response is set to be discussed at cabinet today at 4pm.