Article 17 says how Parliament shall be elected, and empowers Parliament itself to determine who is not eligible to stand for election. Article 26 prescribes the life of Parliament. There is no reference in the Constitution to a member of Parliament, once elected, ceasing to be a member. Therefore, he argues provided the member remains eligible, once elected he remains a member for the life of that Parliament. The Constitution intends that the Republic shall be governed by Parliament.
Parliament can only function if members attend.
There is nothing unconstitutional in a provision designed to ensure that parliament does function, and that a person elected to parliament does what he is elected to do attend Parliament. If he fails to do so, it is reasonable that he should be replaced by somebody who will. There is no procedure laid down in the Constitution for that, so parliament must provide it. It did so in the 1983 Act. The power to unseat in proper circumstances is constitutional.