This is untrue.
Amendment 58, moved by the SNP, proposes to change the wording of sub-clause 1(1), which amends the first section of the Scotland Act. The Bill's original wording simply provides a new section which would read as follows:
"(1A) A Scottish Parliament is recognised as a permanent part of the United Kingdom’s constitutional arrangements."
The proposed amendment would read:
"(1A) The Scottish Parliament is a permanent part of the United Kingdom’s constitution.
(1B) Subsection (1) or (1A) may be repealed only if—
(a) the Scottish Parliament has consented to the proposed repeal, and
(b) a referendum has been held in Scotland on the proposed repeal and a majority of those voting at the referendum have consented to it."
It is being maintained that, by voting against this amendment, the Commons has voted against making the Scottish Parliament permanent.
It is certainly the case that, so long as (1B) were to be on the statute book, there is a significant political obstacle to the repeal of the Scotland Act or the removal of the Scottish Parliament. The political cost of not having procured consent of Holyrood and the Scottish people, having made a written commitment to do so, would be enormous.
In terms of its legal effect, however, this additional sub-clause does not add anything at all. If the concern of the movers of this amendment is that (1) or (1A) might be repealed, one presumes by ordinary legislation in the Westminster Parliament, what is to stop exactly the same piece of legislation from repealing (1B) in the same piece of legislation? Nothing. Any scenario in which the repeal of (1) or (1A) would be in issue could also see (1B) in the firing line.
This actually relates to more fundamental problems with the drafting of the Scotland Bill. The recommendation of the Smith Commission in relation to the permanency of the Scottish Parliament is essentially constitutionally impossible, so long as it is accepted that the Westminster Parliament is legislatively supreme and may make or unmake any law.
The proposed (1A) by the government does not actually make the Scottish Parliament permanent either. It says that it makes it permanent. But what does that mean? If Westminster passed the Abolition of the Scottish Parliament Act that purported to repeal it in its entirety, who would actually stop the Parliament from ceasing to exist? Not the courts. They would take their instruction from the most recent and unambiguous words of the Westminster Parliament. This is no greater legal protection of the existence of Holyrood than the Scotland Act as it stands.
If you were to make the Scottish Parliament permanent, you would need a codified constitution, and you would need to abolish the Westminster Parliament, or at least find a mechanism by which its legislative supremacy is "permanently" or irrevocably constrained. No provision in the Scotland Bill is capable of doing this, because of the principle that no Parliament may bind its successors.
Even if (1A) were capable of making the Scottish Parliament permanent, in terms of the law, (1B) arguably weakens, not strengthens, the protection, by providing a specific exception to the provision of (1A). Any logic that argues that (1B) is immune from repeal must accept that (1A), without (1B), is immune from repeal.
The principle that the Scottish Parliament and the Scottish people should both have a veto over Holyrood's abolition is a perfectly sound one. Neither the government's clauses nor the SNP amendment deliver this.
We need a constitutional convention!