Generally, yes. Intervention orders are usually made ex parte (without the other party present). All evidence submitted to court to support an application should be provided to the other side as soon as practicable so that they other side has a chance to appeal/review the application/order, cross-examine it (if possible) and know what case they have to answer to. It would be extremely prejudicial to the other side if the evidence relied upon that lead to an order against them were not disclosed to them or their representative. There would need to be exceptional circumstances for this to be protected (i.e a very good reason such as protecting a vulnerable person), and even then, only selected information would be blacked out.