They still maintain the tunnel on behalf of Cardiff Council.
Cardiff Council would need to agree a selling price of £5M or less for this to be possible.
Elections to Cardiff Council take place every four years.
Cardiff Council originally planned for the retail park to be built on the current site of the allotments.
In the 1930s Cardiff Council were looking to develop an orbital road system around the city.
Gasson has been an elected councillor to Cardiff Council since 1988.
There are already signs that footfall is improving, according to Cardiff Council.
Cardiff Council in south Wales is elected, as a whole, every 4 years.
Cardiff Council estimated the population of the unitary authority at 317,500 in 2006.
Cardiff Council is planning to develop the site of the leisure centre to include a new secondary school for the area.