The phrase "a powerful ally of" is correct and usable in written English.
You can use it when describing someone or something that provides strong support or assistance to another person or entity.
Example: "In the fight against climate change, renewable energy sources are a powerful ally of sustainable development."
Alternatives: "a strong supporter of" or "a significant partner in".
Environmentalists see in Mr. Wheeler a powerful ally of polluting industries and enemy of clean air and water.
Some say Zeng Qinghong, a powerful ally of Mr. Jiang, phrased the poll question in a way that would help ensure that Mr. Xi came out on top.
They are preparing for that now and are examining the options," Rafsanjani, a powerful ally of Rouhani, was quoted as saying by ILNA news agency on Sunday.
"Musharraf is our problem," said Ahmad Mukhtar, who successfully contested a seat against a powerful ally of Mr. Musharraf, Chaudhry Shujaat Hussein.
The Christian Coalition has been considered a powerful ally of the Republican Party and its presidential nominees since it was created in 1989.
But opponents — who collected 1.3 million signatures to place the repeal vote on the Nov. 8 ballot — say the law unfairly scapegoats public employees, and weakens unions, a powerful ally of the Democrats.
Today, the "open-source revolution" appears more than ever to be a powerful ally for the promotion of development and the narrowing of the economic gap between developed and developing countries.
In his 22 years as Saudi Arabia's ambassador to the United States, a tenure that ended in 2005, Prince Bandar was a powerful ally to a succession of presidents.
On a spiritual level, garnet heightens clairvoyant abilities and is considered a powerful ally for accessing the wisdom of dreams.
Inertia and ignorance are a powerful ally to those who seek control of software markets.
But the top investigator for a government oversight board filed internal union charges last month saying a top Hoffa aide and a powerful ally, the leader of Chicago Teamsters, masterminded a scandal much like those of Las Vegas past.
