The Six Nations match between Wales and Scotland should be called off, Plaid Cymru has said.
Leader Adam Price said all mass gathering events should be postponed or cancelled.
The safety of citizens “must be put before everything else”, Mr Price said.
It comes as the UK government is expected to announce that it is stepping up its response to coronavirus.
Plaid earlier cancelled its own spring party conference, due to be held on 20-21 March in Llangollen.
A Welsh Labour source said changes to its party conference could become inevitable if advice changes later.
Scotland’s First Minister Nicola Sturgeon has recommended that mass events involving more than 500 people should not go ahead.
Mr Price said: “The safety of our citizens – including the most vulnerable and at risk of coronavirus, must be put before everything else.”
He called for the Welsh Government to take “urgent and aggressive action” rather “than waiting for instruction from London”.
They should consider instructing public sector workers to work from home, whether schools should break up early for Easter, the party leader said.
“All mass gatherings and events should be postponed or cancelled with immediate effect – that would mean no indoor gatherings larger than 100 and no outdoor gathering larger than 500.”
“All political leaders must realise that the actions we take now, today, could mean the difference between life and death later on. We owe it to our people and our communities to do the right thing. The public will expect nothing less.
Earlier Plaid Cymru said cancelling its conference “is the most responsible course of action for the party to take in the current circumstances.”
The Welsh Labour event is being held in Llandudno from 27 to 29 March.
A senior Welsh Labour source said: “The party won’t want to run ahead of the official advice from government and medical experts, unnecessarily adding to panic.
“However, if that advice develops in the coming hours and days, changes to conference become inevitable. “Welsh Labour will also be worried about the impact that cancelling could have on Llandudno as the host town, as well as the risk of coronavirus to party members and visitors.”