The UK was scheduled to hold a general election on 7 May 2020 (until the 2017 election was called). If that election were to be scheduled for that date, Parliament would have been dissolved at the end of March.
On 19 March, before the UK enacted its nationwide lockdown, Coventry Council held a by-election for one of their council seats. While turnouts for council by-elections is not usually very high, the turnout at this by-election was only 9% (Coventry Council). It follows that it would be very difficult to see how a general election could be held during this lockdown, especially while maintaining physical distancing.
In the event of an emergency, Parliament would normally be able to change the date of a general election by amending the Fixed Term Parliaments Act 2011. But if Parliament has been dissolved, it cannot change the date of the election. So what options, if any, would be open to the government to delay the election? Could the previously-dissolved Parliament be subsequently recalled? Could one of Her Majesty's reserve powers be used to delay the election? Or would the election have to carry on regardless?