The former prime minister railed against the “Ukip view of being British”, arguing it will be “profoundly patriotic” to vote to Remain in the EU in the upcoming in/out referendum.
In a globalised world there is no alternative but to co-operate with neighbouring countries to boost trade and jobs, fight people smugglers, tackle climate change and compete with emerging economies in Asia and elsewhere, Mr Brown said.
The former Labour leader urged voters not to choose a “future of misery” by refusing to co-operate with other countries but instead come together to create an “insurance policy” in a troubled world.
Writing in the Daily Mirror, Mr Brown also argued that In campaigners cannot rely on business support and trade statistics to sustain their argument.
He said: “Business fact sheets and trade statistics struggle to be relevant in what looks like a culture war that tells us that, because of Europe, Britain is no longer recognisable as the country we were born into and that our distinctive values are under threat.
“So now we have to be up front about what it is to be British in the changing world in which we live.”
He went on: “In contrast to the Ukip view of being British - that we are only at our best on our own and semi-detached - let us remind people of that more profoundly patriotic view - that we stand up for British people’s needs and aspirations best not by choosing splendid isolation but as a proud, outward-looking nation playing our part in the world - fighting our corner for Britain as a leader of Europe.
“Never forget: We are the British people who did not stand aside but led on the mainland of Europe sacrificing everything to overcome fascism, totalitarianism and anti-semitism.
“We are the British people who have more recently led the way in standing up for action against climate change, for debt relief for the poor and for human rights such as the banning of land mines and chemical weapons.
“And we are the British people now able, if we so choose, to lead against the reactionary forces that are now rearing their head across the world - economic protectionism, xenophobic isolationism and anti-immigrant racism.
“We can lead because the rest of Europe is looking for a united front against a military-resurgent but economically-enfeebled Russia, a counterweight to balance the dominance of Germany, a champion of a more democratic, accountable and competitive Europe and someone to lead the fight for jobs under threat from low-wage competition from Asia.”
Mr Brown added: “The message could not be clearer: For trade and thus sustaining millions of jobs, to defend ourselves against terrorists and people smugglers who operate across borders, to prevent unscrupulous competitors in other parts of Europe undercutting us, to use our energy resources such as wind and wave to best effect and to ensure our security and stability, there IS no alternative but to co-operate with our neighbours.”