The former Prime Minister said those arguing for the UK to retain its EU membership must make “a positive case” ahead of the vote on June 23.
In an opinion piece published in the New York Times, Brown said: “The 2014 Scottish independence referendum is a stark reminder of the dangers of excessive negativity. Reaffirming Scotland’s status as part of the United Kingdom required a patriotic vision and a positive, forward-looking mission statement. The same holds true in this referendum.
“Traditional patriotism and modern realities need not be at odds. In an interdependent world, each country must strike a balance between the autonomy it desires and the cooperation it needs.
“In the European Union, Britain can play a constructive role without either subjugating its identity to a European superstate or lurching backward into a ‘Little England’ mind-set.”
Brown’s latest intervention in the EU debate comes as several opinion polls suggest the Brexit camp had gained a slight lead over the Remain side.
The former Labour leader described the campaign so far as “bitter and bad tempered”.
He argued that only by being a member of the EU could Britain shape the future of the union and play a full role in solving global challenges such as climate change.
Brown continued: “A Britain that accomplishes these things will not make any of us less British as a result.
“The high tide of Europe’s federalist ambitions is receding. In its place is a more acceptable model of decision making shared by its 28 national governments. The continent’s future lies not in a United States of Europe, but in a United Europe of States.”
Brown’s intervention in the days before the referendum on Scottish independence in September 2014 were credited as helping the No campaign win over a majority of voters.