The former leader of the Scottish National party, Alex Salmond, has said Westminster politics is “decaying before our eyes” as he issued a rallying cry to supporters of independence.

The ex-first minister of Scotland told a conference of the Scottish Independence Convention that the timing had “never looked better” for the cause. The Build: Bridges to Indy event brought together about 1,600 activists at Edinburgh’s Usher Hall to explore the future of the movement.

Salmond said: “Obviously our strength is great, look around the hall, feel our strength as a movement but also understand the weakness of our opponents.

“I’ve been active in politics for 30 years – elected politics – and I’ve never seen the British state in a state of more disorientation and chaos. We’re Johnny-No-Mates in Europe, not a single friend across the continent.

“The structures of Westminster politics are decaying before our eyes. So this is a matter not just of our strength but their weakness. That also dictates the timing of the campaign and that is another factor for us to consider. I would say the timing has never looked better for the national cause of Scotland.”

Salmond said the platform the movement decided upon would dictate the timing of another referendum, repeating his belief that membership of the European Free Trade Association (Efta) would be the best course for an independent Scotland.

“In that case the referendum must be held at the point of hard Brexit or at the point of transitional agreement beyond hard Brexit,” he said.

Such a position would offer an “island of certainty in a sea of confusion and that would be of enormous value in winning the next independence referendum”.

Salmond, who lost his Gordon seat in June’s snap general election, acknowledged that lessons had to be learned from the previous campaign, highlighting the Scottish government’s white paper on independence. “The independence white paper perhaps strayed too much into the form of a party manifesto as opposed to a national platform.

“But equally, no sane person would suggest that in Scotland we should replicate the empty white sheet of paper that the pro-Brexiteers advocated during the UK referendum. We have to get a balance between offering a vision of a future and having something which is so detailed it goes into what should properly belong in the manifestos of the political parties contesting the first independence election after our constitutional aspiration is achieved.”

Salmond added: “There’s always an understandable reason that people have to say ‘we’re not ready for independence, we’re not ready for another referendum campaign, we’re not ready to move into that again’.

“The only way you overcome these reservations is by leadership going into the campaign. And by leadership I don’t mean one individual or even one political party. I’m talking about the national leadership of a national campaign like this. You have to put the matter to the touch.

“There is an army of interest waiting to be led. The question for us and for the leadership is the platform and the timing that arises from it.”