I have something to say on this point. If you read standing order No. 7 you will find it says:
At the ordinary time of adjournment of the house, unless otherwise provided, the proceedings shall be interrupted and the business under consideration at the termination of the sitting shall stand over until the next sitting day when it will be taken up at the same stage where its progress was interrupted.
Therefore it is clear the government cannot change the item when discussion was started on it.