Speaking weeks after the Panama Papers revelations and with just six weeks to go until the EU referendum, Brown wrote in the Guardian today that it was up to countries to co-operate “when it comes to perhaps the most controversial issue of the moment - rooting out tax havens that deprive our public services of critically needed resources and prevent us having a tax system that people see as fair”.
Labour’s most recent prime minister, whose passionate intervention on the eve of the Scottish referendum was seen as vital in persuading reluctant Labour supporters to back the union, said that the UK should also require overseas territories and crown dependencies to publish public registers of beneficial owners.
Britain cannot achieve this alone ... With America currently resisting reciprocal tax arrangements, collective action by all 28 countries of the European Union to blacklist avoiders, impose sanctions and even levy withholding taxes - on our own overseas territories, if necessary - is currently the one game in town.
In a sign he may be about to take a more visible role in the campaign, Brown also dismissed the claims of those who want to leave the EU and said Britain should not turn its back on globalisation, ahead of a speech he will make at the London School of Economics later today:
“The way forward for Britain - and every other nation - lies in balancing the national autonomy we desire with the continental co-operation we require.
“Britain has always been outward-looking, and engaged with the world – the Britain of traders, missionaries and explorers, who were never insular or isolationist … This vision of a global Britain is now best seen through the eyes of young people – who see no alternative, economically and culturally, to a future in an increasingly interconnected and interdependent world.”
Brown's determined intervention may be seen in contrast to Jeremy Corbyn's initial hesitation to address the EU referendum and concerns from some quarters that he may not be such a full-throated supporter of Britain's membership.
Alan Johnson is leading the Labour campaign to stay in the EU and Corbyn made his first major speech in favour of membership in April - almost two months after David Cameron set the date for the vote.
Brown's statement will echo comments made earlier this week from Corbyn who also addressed the role of EU membership and international co-operation in addressing the abuse of tax havens.