Owen Smith today claimed that any proposals for Labour members to be given the right to elect shadow Cabinet ministers were an attempt to “drive a wedge” between MPs and Jeremy Corbyn.

Smith said such a plan would amount to an attempt by Corbyn to “cement” himself in the Labour leadership, rather than a genuine effort to extend an olive branch to the vast majority of the Parliamentary Labour Party (PLP), which has called on him to step down.

The challenger spoke out following a Sunday newspaper story which said Corbyn could change party rules so shadow Cabinet posts are split between between one third elected by members, those chosen by the PLP and a final tranche picked by the leader.

“I have read the reports… It is being presented as apparently being a conciliatory gesture by Jeremy. It isn’t a conciliatory gesture. It is not simply an attempt to extend democracy in the Labour Party. It is an attempt to deepen divisions between new members and MPs. It is an attempt to further cement his position and use the membership as a means of driving a wedge between the MPs and his leadership,” Smith told Murnaghan on Sky News.

“If he was serious about trying to unify the party then he would taking serious the notion of going back to the traditional method we had of guaranteeing that their was some balance in the shadow Cabinet, and everybody felt in the party they had some representation, which was election through the PLP.

“I am in favour of us having more democracy in the Labour Party, but I don’t think Jeremy and his team can get away with saying this is all about an olive branch, when really and truly it is about deepening the divisions he has created in the party.”

Centrists MPs fear any internal party reforms, of the like described in today’s report in The Observer, would entrench the power of the left and leave them with even less power to influence party policy.

Smith, who stepped down as shadow Work and Pensions Secretary in the summer “coup” against Corbyn, warned centrist MPs against trying to engineer a split or semi-split in Labour, which he said would spell “disaster”, but reiterated that he would not rejoin the shadow Cabinet if the incumbent wins the leadership contest.

“I don’t think I could do that with integrity having spent the summer saying that I don’t think Jeremy is up to the job and I don’t Jeremy is going lead us to victory.

“I think it would be wrong for me then to serve alongside Jeremy but I won’t do what Jeremy did. Jeremy voted against the Labour government and Labour Party… 500 times, I think. I am not going to do that.”

Smith, who is expected to be defeated when the result is declared at party conference, indicated the argument over Labour’s policy and direction will go on when he said the party “will need to continue to have this debate whoever wins on Saturday”.