On Friday, Brendan Cox tweeted:
The tweet was retweeted and liked thousands of times.
Many also replied with praising Mr Cox's words and the way has handled the loss of his wife.
He said: “The dawn is breaking on an independent United Kingdom!
“We have fought against the multinationals, we have fought against the big merchant banks we fought against big politics, we fought against lies, corruption and deceit.
“And today honesty, decency and belief in nation I think now is going to win.“And we will have done it without having to fight, without a single bullet being fired.
“We will have done it by damn hard work on the ground, by people like my friend Mr [bankroller Arron] Banks here. And by people in the Labour party and the Conservative Party and of Ukip and no party.
“I hope this victory brings down this failed project and leads us to a Europe of sovereign states.”
Jo Cox was shot and killed last Thursday in Birstall, near Leeds.
The attack came on the steps of the town library just before 1pm, where the 41-year-old mother-of-two had been holding a surgery with her constituents.
Cox, who was elected to the Commons last year as MP for Batley and Spen, was rushed to Leeds Infirmary hospital by air ambulance after apparently being shot twice and stabbed.
52-year-old Tommy Mair will stand trial for her murder in November.
He is accused of shooting and stabbing Cox, 41, outside her constituency surgery in Birstall, near Leeds, earlier this month.