You may hear the word ‘shadow’ used in relation to prominent members of the Opposition.
The Opposition is usually formed by the political party with the second highest number of MPs in the House of Commons. It is not part of the Government. It is the Opposition’s job to present an alternative to the Government and hold it to account.
Each member of the Government has an opposite number whose job it is to scrutinise them. The word shadow is used to refer to these politicians. If the party in Opposition wins a general election, shadow ministers replace the members of the Government.
So, for example, the Shadow Home Secretary is the member of the Opposition who would deal with home affairs if their party was in Government.
The Shadow Home Secretary will present voters with an alternative way of doing the job. He or she will criticise the Home Secretary if they disapprove of the work they’re doing.