This has probably been answered already in one form or another but grateful for advice please.

When putting together the sponsor's letter in support of my wife's settlement visa application, is it adviseable to include a reference about what I would do if the application were refused - for example, to underpin the assertion that that the relationship is genuine would an ECO expect to see some mention of the fact that I would at least be willing to consider relocating in order to stay with my wife?

Your sponsorship letter should address the requirements of the immigration rules and how you believe your wife meets them. To be willing to relocate should the visa be refused is not such a requirement, but, having said that, if you were to mention it, it wouldn't adversely effect your wife's application.

Scouse.

This has probably been answered already in one form or another but grateful for advice please.

When putting together the sponsor's letter in support of my wife's settlement visa application, is it adviseable to include a reference about what I would do if the application were refused - for example, to underpin the assertion that that the relationship is genuine would an ECO expect to see some mention of the fact that I would at least be willing to consider relocating in order to stay with my wife?

I dont think the ECO is at all concerned what you will do if the application is refused. He is only concerned whether your application satisfies the requirements to settle in UK.