Pope Francis said he does not fear a schism within the Roman Catholic Church, as criticism grows among conservatives of his liberal views on migrants, the protection of the environment and giving communion to divorcees.

Speaking on board the papal plane on his return from a trip to Madagascar, Mauritius and Mozambique, the Pope said he had been unfairly labelled “a Communist” by his critics, with the most vocal being conservative Catholics in the United States.

In his strongest remarks yet on the risk of a schism, he said there had been many doctrinal splits during the 2,000-year history of the Church, although he prayed there would not be another.

“I am not afraid of schisms. I pray that there will be none, because what is at stake is people’s spiritual health,” he told journalists on board the plane.

The Pope’s impassioned defence of migrants and refugees, his opposition to Donald Trump’s wall on the US-Mexico border, his sympathy towards homosexuals and his openness to remarried divorcees being allowed to take communion have earned him the ire of conservatives, particularly in the US.