Question to the Department for Work and Pensions:

To ask the Secretary of State for Work and Pensions, what estimate he has made of the projected number of children under the age of five who live in households that will be affected by the freeze on tax credits and jobseeker's allowance in (a) 2016-17, (b) 2017-18, (c) 2018-19 and (d) 2019-20.

HMRC publishes annual estimates of child and working tax credits.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/613423/cwtc-main-Apr17.pdf

Provisional estimates for 2016/17 show approximately 1.84 million children under 5 living in families in receipt of tax credits.

An Impact Assessment was also published alongside the Welfare Reform and Work Act 2016. This considers impacts of the freeze on households and on protected groups including children and lone parents.

http://www.parliament.uk/documents/impact-assessments/IA15-006C.pdf

However, information on the children of recipients of Jobseekers Allowance (JSA) is not collected, and projections beyond 2016 of children under the age of 5 living in households in receipt of either tax credits or JSA have not been estimated.