"(2) A tribunal may- … (e) subject to paragraph (3), at any stage of the proceedings, order to be struck out any … notice of appearance on the grounds that the manner in which the proceedings have been conducted by or on behalf of … the respondent has been scandalous, frivolous or vexatious; …"
"(3) Before making an order under sub-paragraph (e) or paragraph (2) the tribunal shall send notice to the party against whom it is proposed that the order should be made giving him an opportunity to show cause why the order should not be made; but this paragraph shall not be taken to require the tribunal to send such notice to that party if the party has been given an opportunity to show cause why the order should not be made."