Shadow health minister Diane Abbott has tweeted:
What price xenophobia? Stigmatising foreigners accessing NHS creates a public health risk.
@paulwaugh Agree with charging people who are not entitled to free NHS care. But obvious public health risks re. communicable disease.
Earlier, Labour's shadow health minister Liz Kendall said the government had a "poor record in announcing policies that sound good but prove to be completely unworkable" and they would be asking "many questions" on the proposals.
More top news
Barack Obama has returned to the political spotlight, campaigning for Democratic candidates ahead of upcoming elections.
The prime minister said there was a "clear and urgent imperative" to give new impetus to stalled negotiations.
Pollution claimed nine million lives in 2015, with air pollution from vehicles and factories accounting for 6.5m deaths, researchers found.