There is no power for the judiciary to strike down primary legislation in the UK. Judges have wide interpretive powers and in case of doubt are likely to refer back to parliament with 'did you mean this?' The government then have to respond or clarify? They can rule against the government in a judicial review on legal grounds only, this is not striking down legislation though. The government must appeal or make suitable changes to comply with a ruling. Example; civil partnerships, the law was described as incompatible where opposite sex partnerships were considered, this did not mean that the law was struck down or no longer working. It required the government to amend the law.