Nope it is not valid because those peers are not bothered in being a double check for laws, they are just trying to stop something they dont want to happen. If you and they had anything about you, then you would just admit that. You could admit it with a laugh and a smug shrug of the shoulders. I have said on here for a while that Brexit would not happen because of the Lords.
The unelected elite in this country were going to do anything to "kick it into the long grass" and keep the process tied up in courts. We all knew it was going to happen, and when it did I committed myself to help the BLA in any small way I could.
The great thing is by doing this they are storing up so many problems for the future I am more convinced then ever that the way the EU has treated us will show other countries how authoritarian they are. Also we will hopefully in some point in the future get a true democracy which will include and elected second house, not the situation now where whoever gets into power just get rid of Lords that are not of the same political persuasion as them.