The phrase "as a strong backer of" is correct and usable in written English.
It can be used when expressing support or endorsement for a person, organization, or cause.
Example: "The senator is known as a strong backer of environmental policies that aim to combat climate change."
Alternatives: "as a firm supporter of" or "as a staunch advocate for".
By doing so, Mr. Putin has burnished his domestic image as a strong backer of his national security establishment.
She held conversations with senior adviser Kellyanne Conway and others as her allies touted her as a strong backer of the president.
Known as a strong backer of India's nuclear establishment, Singh in 2008 staked the future of his government on passage of the landmark Indo-U.S. civilian nuclear agreement, which allows India, once ostracized over its nuclear weapons program, to buy civilian nuclear technology.
"Although I'm not a liberal, I always felt like there was nobody that listened to his constituents more," Mr. Kurker said, explaining why as a moderate independent he had become such a strong backer of Mr. Kennedy.
The Mail has been a strong backer of May, seeing her as much the most plausible Tory leader in the aftermath of David Cameron's resignation, and contrasting her ostensible gravitas with the lightweights in her cabinet.
Mr. Belka, 51, who is known more as an economist than a politician, is considered a strong backer of the United States.
Beijing's central government "has always been a strong backer of Hong Kong" and "will, as always, support Hong Kong's economic development and improvement of people's lives".
Culberson, a strong backer of Trump, is seen as highly vulnerable after the city was devastated by Harvey.
Ms. Baldwin is a strong backer of President Obama's policies, while Mr. Thompson, who served as health and human services secretary under President George W. Bush, denounces the new health care law and warns that the country is sliding miserably toward disaster.
