Foreign Office minister Mark Field said he will write to Hong Kong's chief executive following what Speaker John Bercow described as "utterly scandalous" treatment of Benedict Rogers.
Bercow said those responsible for the decision to bar entry "have certainly heard the last of it".
Rogers, of the Conservative Party's Human Rights Commission, told Premier he was turned away by immigration officials after arriving at Hong Kong airport earlier this month.
Speaking in the Commons, Tory MP Fiona Bruce (Congleton) said: "Do ministers share concerns and if so what action is the Foreign Office taking at the apparent continuing erosion of the one country, two systems principle in Hong Kong following booksellers' disappearances, the recent imprisonment of a democratically-elected representative and last week the refusal of entry into Hong Kong on a purely private visit of UK citizen and human rights campaigner Ben Rogers, who is watching our proceedings today?"
Field said UK-Hong Kong relations remain broadly strong, adding: "However, I very much accept her position that we are very concerned that Ben Rogers was denied entry to Hong Kong on October 11 in absolute disregard of the one country, two systems principle.
"The Foreign Secretary issued a statement and the Foreign Office director general for economic and global issues summoned the Chinese ambassador on this issue over the past few days.
"We've also made representations to both Beijing and I shall be writing to Carrie Lam in Hong Kong in the days ahead."
Bercow thanked Field for his remarks and for Boris Johnson's statement on the issue.
He said: "Ben Rogers is an outstanding and articulate champion of freedom, democracy, human rights and the rule of law in Asia and elsewhere, well known to members on both sides of the House and his treatment was frankly utterly scandalous.
"Those responsible have certainly heard the last of it - of that I think we can be sure."