LONDON, Sept 16 (Reuters) - British retailer Marks & Spencer (MKS.L) said it would close all 11 French franchise food stores it runs with its partner SFH because trade rules in place since Britain left the European Union had hammered product availability. M&S said on Thursday that its remaining nine French franchise stores, run with Lagardere Travel Retail (LAGA.PA), will continue to trade and the pair were working on a sustainable future business model. Chairman Archie Norman has complained for months that M&S was struggling to get goods into Ireland and France since Britain left the EU single market at the beginning of the year, due to the huge amount of extra paperwork. read more "M&S has a long history of serving customers in France and this is not a decision we or our partner SFH have taken lightly," Paul Friston, M&S" international director, said. "As things stand today, the supply chain complexities in place following the UK’s exit from the European Union, now make it near impossible for us to serve fresh and chilled products to customers to the high standards they expect, resulting in an ongoing impact to the performance of our business," he added. The 11 stores that will close by the end of this year are located predominantly across the high streets of Paris, while the nine run by Lagardere are located in travel hubs such as airports, railway and metro stations.A spokesperson for Prime Minister Boris Johnson defended the Brexit process. "We believe that the approach we have taken is the correct one. It is something that the public voted for and it is already bringing benefits to the public," the spokesperson said. The government had also provided significant funding, advice and support throughout the Brexit period so companies could prepare and understand the changes, they added. In April, M&S reconfigured its food business in the Czech Republic to remove supply chain risks. It took all fresh and chilled products from its stores, and doubled ranges of frozen and ambient products. Last month, M&S upgraded its profit outlook after a jump in demand for food in its home market and a surge in online clothes sales indicated that its latest turnaround plan was starting to deliver. read more