How to say “Politely end a relationship” professionally

Level 1: Thank you for considering me for this initiative. After reviewing my current commitments and the projected timeline, I've identified potential bandwidth constraints that might impact delivery excellence. Would it be possible to re-evaluate my involvement or explore alternative resource allocation?

Level 2: I appreciate the opportunity. To ensure all current priorities receive the necessary focus, I've outlined my ongoing contributions. Given this, aligning with this new initiative effectively might require a strategic re-prioritization across the team, which I'd be happy to support.

Level 3: Per our last sprint retrospective, my Q3 OKRs are already at 110% capacity, primarily focusing on Project X's critical path items. While I'm always keen to expand my 'value add,' perhaps we should consult the RACI matrix or the original SOW to align on resource optimization for this new engagement.

Level 4: I need to respectfully decline taking on this new responsibility. My current workload does not permit additional commitments without compromising the quality of existing deliverables. Let's discuss how best to address this gap.

Level 5: No.

Level 1: After careful consideration of project progression and mutual objectives, we believe it's in the best interest of both parties to conclude our engagement on [Project Name] as of [Date]. We are committed to ensuring a smooth transition and will provide all necessary documentation and support during this period.

Level 2: Following our recent strategic review, we've identified that the current scope of [Project Name] may no longer fully align with the evolving needs of both our organizations. To optimize future outcomes, we recommend transitioning to a new phase or exploring alternative solutions that better support your long-term vision.

Level 3: As per the original Statement of Work (SOW) Addendum 3.1, the agreed-upon project parameters and deliverables for [Project Name] have been fully met. Any further 'iterations' or 'pivot explorations' would necessitate a new engagement agreement, reflecting an entirely new scope and associated budgetary implications. Our billing system is fully equipped to generate a new proposal at your earliest convenience.

Level 4: We are unable to continue with [Project Name] beyond [Date]. The current trajectory is unsustainable given the agreed-upon resources and objectives. We will provide a final handover package by then.

Level 5: We're done.

Level 1: I understand you're facing a deadline. While I'd typically be able to assist, my current focus is on [specific task/project]. Have you considered reaching out to [another team member] who might have more bandwidth, or exploring resources in [relevant documentation]?

Level 2: I'm currently fully immersed in [your priorities]. To ensure we both maintain optimal productivity, it might be beneficial to review our respective bandwidths and project allocations if this is a recurring need. Let's ensure our efforts are strategically aligned.

Level 3: Ah, another 'urgent' request outside the defined JIRA ticket workflow. While I appreciate your faith in my 'synergy-generating' capabilities, I believe the process map clearly delineates the ownership for [specific task]. Perhaps a quick refresher on our team's RACI chart is in order?

Level 4: I cannot take this on. My priority is [your task], and I need to focus on my deliverables. You'll need to find another solution for this.

Level 5: Figure it out.