Writing in the Guardian, Mr Blair said: "It doesn't matter whether you're on the left, right or centre of the party, whether you used to support me or hate me," he wrote.
"But please understand the danger we are in.
"The party is walking eyes shut, arms outstretched over the cliff's edge to the jagged rocks below.
"This is not a moment to refrain from disturbing the serenity of the walk on the basis it causes 'disunity'.
"It is a moment for a rugby tackle if that were possible."
"But please understand the danger we are in.
"The party is walking eyes shut, arms outstretched over the cliff's edge to the jagged rocks below.
"This is not a moment to refrain from disturbing the serenity of the walk on the basis it causes 'disunity'.
"It is a moment for a rugby tackle if that were possible."