Autumn Statement

The Spring Statement of the British Government, also known as the "mini-budget", is one of the two statements HM Treasury makes each year to Parliament upon publication of economic forecasts. The other taking place the year before as the Autumn Budget. In 2016, it was decided the budget would move to the autumn, with a spring statement taking place the following year. both usually involve speeches in the House of Commons by the Chancellor of the Exchequer. There are expected to be two Budget speeches in 2017, followed by a Spring Statement in 2018.

The duty to publish two annual economic forecasts was created by the Industry Act 1975, with the first such publication occurring in December 1976. The first Autumn Statement combined the announcement of this publication with any announced changes to national insurance contributions and the Government's announcement of its spending plans (and publication of the Red Book), both of which were also made at approximately the same time in the parliamentary year.

In 1993, Conservative Chancellor Kenneth Clarke combined the announcement of spending with the Budget, merging tax and spending announcements. Doing so moved the Budget to November. To fulfill the legal obligation to make two statements, Clarke began the practice of making a Summer Statement focusing on economic growth forecasts. Unlike the Autumn Statements preceding them and the Pre-Budget Reports that replaced them, Summer Statements took the form of debate on a motion "that this House welcomes the publication of the Government's latest economic forecast, which..." rather than as a statement to the House of Commons.

In 1997, Labour's new Chancellor, Gordon Brown, moved the Budget back to spring and replaced the second statement with the Pre-Budget Report (PBR). According to the "Code for Fiscal Stability", published by HM Treasury in November 1998, the PBR was intended to "encourage debate on the proposals under consideration for the Budget". The PBR included a report on progress since the Budget, an update on the state of the national economy and the Government's finances, and announcements of proposed new tax measures and consultation papers.

...
Wikipedia