Marshall, speaking at a stakeholders' event at the south London-based NCGMA, said he was pleased new Covent Garden Market Authority chief executive Daniel Tomkinson acknowledged the "challenge" of the market moving to new buildings nearby as the Nine Elms area of Vauxhall is redeveloped, with large areas of market land being sold off.
But salads seller Marshall said the release of public sector land to build homes and redevelop the Nine Elms site has a downside for traders: "This great market will continue to supply food to London. But the food market is full and the flower market is full. They will have tough times going into smaller premises, But we are determined to make our market work. We have had up to now we believe a very rough deal. We believe the market is too small and there is too much interest with luxury flats rather than people who work in the area. But we will remain the number one market in London and hopefully will become the number one market in Europe."
The 30 businesses will move to a smaller 4,650sq m (50,000sq ft) building.
Scross the 200 hectares of Nine Elms, there will be around 20,000 homes. On market land sold to fund the new market there will be a total of 3,000 homes. The redevelopment of the market is being funded through a land swap.
The interim flower market is due to open in February 2017. The new fruit and veg market opens in 2020.