There is anger among unionists and loyalists at the post-Brexit trade arrangements which see the region treated differently to the rest of the United Kingdom to avoid placing a hard border in Ireland.
The declaration, organised by the Orange Order, was signed on tables covered in Union flags at an estimated 250 Orange Halls across Northern Ireland.
The initiative had echoes of the signing of the Ulster Covenant in 1912 against home rule in Ireland. That was signed by almost 500,000, some reportedly with their own blood.
Harold Henning, deputy grand master of the Orange Order, said the declaration is in support of the anti-protocol stance taken by leaders of the unionist parties.
He said there is strong feeling against Northern Ireland being treated differently to the rest of the United Kingdom, and the impact this has on businesses.
Mr Henning, who visited several of the halls where the declaration was signed, said people are frustrated.
There was also an opportunity to sign the declaration online.
Mr Henning said they will not know the total number of signatures until they are collated next week, but said he assumed tens of thousands have already signed it.
“When you have all the unionist-elected politicians against the protocol, why is the message not getting through?” he told the PA news agency.
“People are coming out to sign and say, ‘hold on, listen to us’.
“At this stage we are leaving it to our politicians to try and sort this out, and I hope they can do it, and I hope our Prime Minister listens, and I hope Europe listens, because thus far, they have not been listening.”
Mr Henning said the declaration will be presented to Mr Johnson at Downing Street.
Earlier this year, demonstrations against the protocol organised on social media were followed by rioting, but Mr Henning described the declaration as a “peaceful means to express frustrations”.
He added there could be further moves taken if deemed necessary.
“There will be more, this is one part at this time and we’ll see what progresses, but hopefully they’ll listen,” he said.
“I don’t think there will be another declaration but there will be moves in other directions to keep the pressure on and get the message out to Dublin, Europe, and to our Prime Minister, who needs to listen to the unionist people of Northern Ireland.
“It may be more gatherings, rallies, that’s in the future. At the minute, it’s being left to the politicians to do their best to sort it out.”
DUP MP Carla Lockhart was among those who signed the declaration at Carleton Street Orange Hall on Saturday.
She said it was great to see a “steady stream of people” joining in.
“It shows the strength of feeling there is on the ground amongst the unionist people against the protocol, the damage it is doing economically and constitutionally to Northern Ireland,” she said.
Talks remain ongoing between the UK and EU about the protocol under which Northern Ireland effectively remains in the single market for goods.
This helps to avoid a hard border with Ireland but increases checks and barriers to trade on goods crossing the Irish Sea from Great Britain, making it a source of tension in unionist communities.
The DUP has urged the Government to trigger Article 16 of the protocol, which would suspend parts of the agreement and risk a major escalation in tensions with the EU
Ms Lockhart added: “We at Westminster will continue to fight the protocol, we will continue to urge the government to urgently act and trigger Article 16.
“The protocol must go.”