Sir Lindsay Hoyle has insisted he will suspend Commons proceedings if they get too crowded after the Government pressed for MPs to return within weeks.
The Commons Speaker said everyone on the parliamentary estate must be kept safe and social-distancing rules must be complied with.
The requirement for two metres between people means only 50 MPs can attend the chamber in person, while up to 120 can join proceedings remotely via Zoom.
Commons Leader Jacob Rees-Mogg announced on Tuesday that he does not want to see the so-called “hybrid” arrangements extended beyond the Whitsun recess, which ends on June 2, thereby requiring MPs to attend in person to take part in proceedings.
He added that Parliament must “set an example” to the country, although his remarks surprised opposition parties and led to criticism, given the current social-distancing rules to combat the spread of Covid-19.
On Wednesday, Mr Rees-Mogg said it would be wrong for MPs to “hide away whilst schoolchildren are going back”, but conceded physical sittings may not fully resume in early June if the guidance steers away from it.
Making a statement to the Commons, Sir Lindsay said: “My priority and the priority of all, I’m sure, is to ensure that those on the estate are safe while business is facilitated.
“I’m working with parties, the Commission to ensure this duty of care is taken seriously.
“Nothing in the Leader’s announcement changes the position on social distancing in and around the chamber and throughout the parliamentary estate – only changes to the guidance from Public Health England can do that, I think we’re all agreed on that.
“I may suspend sittings between items of business to allow safe access to and exit the chamber. I’m also quite prepared to suspend a sitting if I believe the safe number of honourable members in the chamber risks being exceeded.”
Sir Lindsay said votes in person would take around 30 minutes, possibly up to an hour, to observe social-distancing rules if electronic voting was no longer allowed.
Prior to the lockdown, MPs had eight minutes to cast their votes and the result would follow a few minutes later.
Electronic voting, which takes 15 minutes, with the result announced later, was used for the first time on Tuesday.
Mr Rees-Mogg, speaking after Sir Lindsay’s statement, said: “It is obviously important that this House maintains social distancing in accordance with the guidelines.”
Bringing back the @HouseofCommons in physical form within weeks could breach the government's own rules on workplace safety.
— Prospect Union (@ProspectUnion) May 13, 2020
For Labour, shadow Commons leader Valerie Vaz said: “Our casework has increased massively, we may not be in the chamber but we still are dealing with our constituents as we always do when we’re not here.”
She added: “The House must lead the way in protecting the health and wellbeing of everyone who works in Parliament by following public health advice to the letter.”
Mr Rees-Mogg accused opposition MPs of trying to “hide behind a veneer of virtual Parliament”.
He also said: “The intention is for schools to go back. How can we say to our schoolchildren, ‘you’re safe going back’, some of them, but that we’re not, that we’re going to hide away whilst schoolchildren are going back – is that the right message to give to our constituents?
“Are we a people set apart, a special class who are exempt from what the rest of the country are doing? No, we are not, we are the leaders of our nation and we have a responsibility, that responsibility falls on us to come back.
“But we can observe social distancing, we can look at the chamber as it’s set out, we can look at the division lobbies that have been arranged by you Mr Speaker to make sure that the clerks are safe and that members are safe.
“This is the right way for us to proceed so that there is proper democratic scrutiny and legislation may be brought forward in accordance with the mandate that the British people gave us.
“Stay at home, work from home if you can. We in reality cannot and that is why we will be coming back.”
Garry Graham, deputy general secretary of the Prospect union, warned that a quick return could create a “massively-elevated risk” to parliamentary staff.