Nigel Farage has launched his general election campaign by saying his Brexit party will contest every seat in the country unless Boris Johnson agrees to drop his deal with the EU and sign up to a “leave alliance”.

The former Ukip leader also praised Donald Trump for his intervention in which he suggested the prime minister and the Brexit party should form an alliance.

At the launch in central London on Friday, Farage said his message for the prime minister was: “Drop the deal because it’s not Brexit. Drop the deal because as these weeks go by and people realise what you’ve signed up to … people will not like it.

“Simply, it is not Brexit. What we’re doing here is kicking the can down the road.”

He said Johnson’s deal would not “get Brexit done”. Rather, it would “lead to a campaign in which people will say we have no voice, no vote, no veto. It will lead to a campaign for us to rejoin [the EU].”

The party is advocating a no-deal Brexit, which it brands as “clean”, so it can leave the EU on World Trade Organization terms and secure free trade deals around the world. It is also pushing for voting reform, the abolition of the House of Lords in favour of an elected second chamber, and the creation of a written constitution.

Farange criticised the “broken promises” of all politicians and reserved some of his most stinging criticism for Jeremy Corbyn’s party, in a sign his own party will be targeting Labour seats.

He said the Brexit party would focus on north-east England, the Midlands, Wales and east London, and had the potential to run in 650 seats if Johnson did not enter a leave alliance. He said his party had until 14 November to come to an agreement with Johnson on seat numbers.