PHILADELPHIA, Pennsylvania — A protest against the Trans-Pacific Partnership free trade deal broke out on the floor of the Democratic National Convention at the Wells Fargo Arena on Monday afternoon, in the midst of an address by Rep. Elijah Cummings (D-MD).

Delegates, many of them wearing Bernie Sanders T-shirts, unfurled a large banner reading: “Economic Justice, Climate Justice, Trade Justice.” They began shouting “No TPP!”

Signs opposing TPP began appearing across the arena, as other delegates picked up the chant.

In the run-up to the convention, Cummings was in charge of drafting the party platform, which excluded opposition to TPP at the direct request of President Barack Obama, according to the Washington Post.

The Democratic platform merely includes a list of demands that are to apply to all trade agreements, including the TPP.

Cummings was in the midst of speaking about the Black Lives Matter movement, but delegates apparently wanted to make sure they interrupted him while they had the opportunity.

Opposition to TPP has been a major feature of protests around the convention. Supporters of Bernie Sanders told Breitbart News that it was a major reason they opposed Hillary Clinton’s vice presidential pick, Sen. Tim Kaine (D-VA). Some Sanders delegates apparently intend to stage a “mutiny” against the pick.

On the Republican side, opposition to TPP has also featured in Donald Trump’s campaign. Trump says he is for free trade, but against deals that benefit other countries at the expense of the United States, and that enshrine special interests.

In Philadelphia, protests against TPP both inside and outside the convention hall were accompanied by anti-Hillary Clinton chants and jeers. When House Minority Whip Steny Hoyer (D-MD) told the convention, “We are here to nominate Hillary Clinton,” there were loud boos.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. His new book, See No Evil: 19 Hard Truths the Left Can’t Handle, is available from Regnery through Amazon. Follow him on Twitter at @joelpollak.