Pascal Lamy, the former head of the World Trade Organisation, has called for the international body’s mandate to be modernised and expanded, and bemoaned the years of negotiations lost to “decontaminating” members’ politically driven proposals.

In an interview with the Financial Times, Mr Lamy struck out at French politicians and the US Congress, saying that when it came to trade they came from the same “parent animals”. Mr Lamy said: “They are the same species. They’ve got the same reaction to trade: they bark. Others sing about trade. They bark” in protest at the issue of opening up trade.

The intervention of the French former director-general, who stepped down after his second four-year term expired at the end of August, comes as negotiators try to close the first global deal in more than a decade to ease the flow of goods through borders.