See below for some links to the Brexit legal challenges (there may be more but everyday something else is found or reported)
Gina Miller vs the Government (anti-Brexit)
Jolyon Maugham's Legal Challenge (Various) to Brexit - Good Law Project (anti-Brexit)
Bill Cash, Michael Tomlinson, Suella Braverman & David Jones's legal challenge to the government’s attempt to extend Article 50 (pro-Brexit)
Possible Legal Challenge from Germany on Extension Date (anti/pro Brexit?)
Robin Tilbrook - English Democrats Challenge the extension of article 50
The English Democrats claim Mrs May did not have the power to extend Brexit past March 29, the original deadline for the UK's exit from the European Union. Group leader Robin Tilbrook has launched a High Court battle claiming the UK has already left the EU and in the judicial review application, the former appeal judge took to social media to confirm his case was considered to be strong.