Chancellor of the Exchequer, Philip Hammond, delivered his Budget statement to the House of Commons on Wednesday 8 March 2017. Jeremy Corbyn, Leader of the Official Opposition, responded on behalf of the Opposition.

What happens after the Budget statement?

It is customary for the Leader of the Opposition to respond to the speech given by the Chancellor rather than the Shadow Chancellor. The Shadow Chancellor makes his response the day after the Budget statement during the Budget debates.

http://www.parliament.uk/budget