Conservative Leader Pierre Poilievre is calling for the federal government to block Royal Bank of Canada's $13.5-billion takeover of HSBC Canada as a way to help with housing affordability.

Poilievre says in a statement that Canada's banking sector is overly concentrated, and that Finance Minister Chrystia Freeland should stop the deal to improve competition in areas such as mortgage rates.

RBC spokesman Andrew McGrath says in a statement that the takeover is in the best interest of HSBC Canada clients and that the Competition Bureau's review did not identify Competition Act concerns with the deal.

In its review, the federal regulator said the takeover wouldn't likely result in a substantial lessening of competition.

The deal must still be approved by Freeland, whose decision will be informed by the regulatory review processes, says Katherine Cuplinskas, a spokeswoman for the minister.

Critics have been pushing to block the deal since it was announced in November last year, arguing that HSBC Canada adds important market pressure especially in areas like mortgage rates and climate policies.