Many people who live in the area where the potash mine could be built say that they are worried that, if built, it could spoil one of England's most beautiful areas.
More top news
The constituency of Washington and Sunderland West includes the UK's largest car plant, which was opened by Nissan in 1984.
This seat was formed prior to the 2010 General Election, taking in Sunderland city centre and the Ryhope area to the south.
The constituency of Stockton South includes relatively affluent areas like Yarm and Eaglescliffe.