"It may be one of those situations where New Zealand just simply has to say 'while our preference would be the Security Council [to deal with the Syria issue] we can understand why unilateral action has been taken.
"If that is the call we make, then I think we will do that irrelevant of the consequences for the Security Council [bid]."
He was not proposing a parliamentary vote but an opportunity for a leaders' debate through the delivery in a ministerial statement.
He was not sure how Labour would respond but he was sure the Greens would vote against it "if we decided to support them."
Mr Key was pivotal last week in getting leaders at the Pacific Islands Forum last week to agree to a strongly worded statement not only calling for individual and collective leadership from the Security Council but laying the blame at the August 21 chemical warfare attack against civilians at the Bashar al-Assad regime.
He said he was relying on information supplied by partners such as British Prime Minister David Cameron who was certain it was not possible for the attack to have been conducted by the rebels.
"On that basis we were happy to accept that wording."
He was not yet sure whether the cabinet would need any further evidence before deciding on a final position for New Zealand.
"We would make that call on the merits of the information we have been provided and whether we think we broadly speaking exhausted the likely options available to us through a multilateral approach," he said.
"I would maintain whatever we made, it would still very much reflect that New Zealand runs independent foreign policy."
He accepted that whatever position New Zealand took it might have implications for New Zealand's bid to join the Security Council.
Every decision the Government had taken had the potential to win or lose votes "and I have no doubt that might fit in that category."
"On the other side of the coins, the lens that we will really be looking through this issue at is whether we believe that some action is warranted - even if the UN won't support it - on the basis of the issue rather than the broader issue of New Zealand wanting to get on the Security Council."