The executive is "struggling" to avoid a breakdown between the DUP and Sinn Féin, Alliance leader David Ford told the Liberal Democrats' annual conference in Brighton.
The South Antrim assembly member said that the power-sharing government was "directionless".
He said Sinn Féin and the DUP "seem prepared to go to any lengths to avoid making any difficult decisions".
"Our executive's watchword seems to be consult, consult and then consult some more, lest you be forced into actually making a decision," the Alliance leader said.
Mr Ford also said during the speech on Wednesday that most DUP and Sinn Féin members still "distrust one another profoundly".
"In council chambers across Northern Ireland they still prefer to squabble over non-issues rather than getting down to delivering better services together," he said.
South Belfast assembly member Anna Lo, who also took part in the Alliance presentation, said her party wanted to see the executive make genuine steps to tackle division and segregation.
"In greater Belfast there are just a handful of mixed public-sector housing estates. The state must meet the demand of people who don't have the means to buy their way into a mixed community free from paramilitary influence," Ms Lo said.
She also said the north's economy desperately needed more growth.
"Our public finances are in a mess," she said.
"Half our public spending comes from subsidies from Great Britain and 71% of our gross domestic product is generated by the public sector."