When is the recall put to the vote?

UK Public General Acts, Recall of MPs Act 2015, accessed 26 January 2021

14. Determination of whether recall petition successful

(2) As soon as reasonably practicable after the end of the signing period, the petition officer must—

(a) determine whether the recall petition was successful,

(b) notify the Speaker that the recall petition was successful or unsuccessful, as the case may be, and

(c) having done that, give a public notice of the outcome of the recall petition in accordance with regulations under section 18.

(3) For the purposes of this Act, a recall petition is successful if the number of persons who validly sign the petition is at least 10% of the number of eligible registered electors.

“The number of eligible registered electors” is the number of persons registered in the register of parliamentary electors for the constituency on the last day of the signing period excluding those who, according to their entry in the register, are aged under 18 on that day.

15. Effect of successful petition

(1) If the petition officer notifies the Speaker under section 14(2)(b) that the recall petition was successful, the MP's seat becomes vacant on the giving of that notice.

A recall petition becomes automartically successful if the number of persons who validly sign the petition reaches at least 10% of the number of eligible registered electors.