The phrase "assembling opposition" is correct and usable in written English.
It can be used in contexts where one is gathering or organizing a group of people or ideas that are in disagreement or conflict with something.
Example: "The activists are assembling opposition to the proposed legislation, hoping to influence the decision-makers."
Alternatives: "gathering dissent" or "mobilizing resistance".
Rapidly, Allan became notorious for his bitingly quick wit, propensity to utter the outrageous and determination to assemble opposition to any motion he had not proposed himself.
Ivanishvili assembled an opposition coalition, Georgian Dream, to take on the ruling party during this year's parliamentary elections, scheduled for October.
Mr. Kibaki, who has pledged to end years of corruption and economic stagnation under Mr. Moi, has improved his chances by assembling a broad opposition alliance, seeming to end the disunity that has previously hampered the opposition.
Using the JD as the cornerstone, he soon began assembling a larger nationwide opposition coalition called the National Front (NF), which contested the general parliamentary elections of November 1989.
When the opposition assembled at the Holiday Inn, that became a target.
In October Gregory's legates and leaders of the German opposition assembled at Tribur (modern Trebur, Germany) to decide the future of the king, who by this point had been abandoned by his last adherents.
That is, by the way, my main line of business: My firm (Mair Strategies LLC) assembles and distributes opposition research, especially to online media, in advancing our clients' objectives (mostly corporate, trade association and charitable clients; we actually do very little political work).
Warbrick encountered challenges assembling the side; there was opposition from some players in including part-Māori in the squad which prompted several early recruits to withdraw.
And it's perfect fodder for Democratic opposition research operatives who are already assembling a dossier on Mr. Romney.
So must the outgoing PM immediately resign and pass the reins to the Leader of the Opposition, even if their chances of assembling a parliamentary majority look slender?
