Comments by the parliamentary secretary to Communications Minister Malcolm Turnbull prove the Coalition lied about cost blowouts to the national broadband network to win votes, opposition communications spokesman Jason Clare claims.

At the Tech Leaders forum on the Gold Coast on Sunday, federal MP Paul Fletcher admitted the Coalition's claim that Labor's NBN would cost more than $90 billion, not $37.4 billion as tabled by Labor, was wrong.

"They made that figure up": Jason Clare. Credit:Dallas Kilponen

In a speech that criticised the former government, Mr Fletcher said the NBN strategic review released in December proved the Labor party had mismanaged the rollout and got the cost wrong.