After missing his chance, Seymour told the Herald: "The fact that they took advantage of me being caught up answering journalists' questions shows how little regard they have for Parliamentary democracy."
The Government would have "forced urgency on us anyway".
Seymour still intended to be the only MP to oppose the Government's bill to ban military-style semi-automatic guns at the first reading.
"The gun laws need to change, but there are much better ways than this," he said.
The Government introduced the legislation yesterday and the Arms (Prohibited Firearms, Magazines and Parts) Amendment Bill will have its first reading today.
National will vote with the Government to pass the legislation through its first reading.
Seymour said interim measures had already made selling military-style semi-automatic weapons and assault rifles to people with A category gun licences illegal.
He said that "good intentions and abrupt action do not guarantee good and lasting outcomes".
"There is a very real danger that we will make a bad law in the process."
His comments come after the Police this morning released its Interim Supplementary Analysis on the legislation.
Although giving more clarity around the proposed law, the analysis was "constrained by the tight timeframes" given the bill was being rushed through the House under urgency.
It said the final details of the bill were being work on right up until it was due to go before the Cabinet yesterday.
"Without these, it is difficult to identify with accuracy the impacts and risks of the proposal.
"This equally applies to details in the buyback scheme which is unlikely to be fully resolved until after the bill is introduced to Parliament."
Because of these factors, the Police's analysis was only general – "but has been included to signal the clear intent of the Government to compensate people who surrender prohibited firearms during the amnesty period".
Police said there was a risk of a black market for firearms being created because of the new law.
"The most likely source of a black market in prohibited firearms in New Zealand would be from the unknown quantity of semi-automatic centrefire and certain shotguns that are held on a standard firearms license, or already held illegally that are not surrendered to Police.
"This particularly applies to guns that have been sold privately."
But Police said despite this, the bill is expected to create an overall safer environment for New Zealand.
As well as banning military-style semi-automatics, the Government also plans a buyback of guns as well.
Speaking to Radio New Zealand this morning, Acting Prime Minister Winston Peters said that cost of such a policy could be as high as $300 million.
Speaking to media this morning, Police Minister Stuart Nash said although the Government had given the $100m-$200m estimate for the buyback scheme, it could be higher still given it was unknown how many would-be banned guns are out there.