article_snippet: May has shelved a decision on whether water cannon can be used on the streets of Britain until after the election, in a major snub to Boris Johnson.
article_snippet: May has refused to sign off the controversial riot control machines despite pressure from the London mayor, who last year spent £220,000 buying three cannon for use in public order emergencies.
article_snippet: Said Home Office sources confirmed last night no ruling on permission would be made this side of the election.
article_snippet: But in the past Theresa has expressed concerns about whether they fit with the British model of policing and is thought to have concerns about they safety.
article_snippet: The standoff over the issue cast light on the ongoing rivalry between the two, both of whom are seen as potential Tory leadership candidates should David Cameron lose the election and step down.
article_snippet: May Home Office has been locked in a row with the London Mayor over the decision to buy the controversial riot control machines and whether the controversial riot control machines fit with UK policing .
article_snippet: Last night City Hall sources insisted Boris Johnson had known about the timetable for some time and was ‘very relaxed’ about the delay.
article_snippet: Mrs May and Mr Johnson two regularly appear at or near the top of polls on who Tories would like as a future leader.
article_snippet: Mrs May is known to regard the London Mayor as a 'faintly ridiculous' figure.
highlights_snippet: Said Home Office was 'highly likely' to approve their use, sparking a row .
  
highlights_snippet: Decision seems to have backfired after Ms May refused to sign off on use .