CARACAS, Venezuela — President Hugo Chávez requested temporary decree powers on Tuesday from the National Assembly. The request, submitted less than a month before a new legislature convenes with a bolstered faction of opposition lawmakers, opens a new phase of tension between the president and his critics.

The move was not unexpected. Legislators have granted Mr. Chávez decree powers three times during his 12-year presidency. He used a decree in 2008 to name regional political leaders with separate budgets, offsetting gains by the opposition in state and municipal elections.

Mr. Chávez said the decree powers, which would last one year, were needed to quickly address floods and landslides that had left tens of thousands of people homeless in Venezuela. Facing criticism over the move, he suggested on state television that his opponents needed to take “a Valium, or something like that.”

“Otherwise, they should see a psychiatrist to get some recommendations,” he added.

The timing of the request suggests that the political sagacity that has served Mr. Chávez throughout his presidency is not waning. Venezuelans are preparing to go on vacation this month, when many businesses and institutions virtually cease operating. Mr. Chávez has used such lulls in the past to announce measures aimed at weakening his opponents.