During the 1960s, the ceremony of assenting by commission was discontinued and is now only employed once a year, at the end of the annual parliamentary session. In 1960, the Gentleman Usher of the Black Rod arrived to summon the House of Commons during a heated debate and several members protested against the disruption by refusing to attend the ceremony. The debacle was repeated in 1965; this time, when the Speaker left the chair to go to the House of Lords, some members continued to make speeches. As a result, the Royal Assent Act 1967 was passed, creating an additional form for the granting of royal assent. As the attorney-general explained, "there has been a good deal of resentment not only at the loss of Parliamentary time that has been involved but at the breaking of the thread of a possibly eloquent speech and the disruption of a debate that may be caused." The granting of assent by the monarch in person, or by commission, is still possible, but this third form is used on a day-to-day basis.

During which decade was assention by commission discontinued?