Had the letter of intent been superseded by a contract incorporating the standard JCT Terms?
Links
[1] https://www.fenwickelliott.com/sites/default/files/Legal%20Briefing%2032-2008.pdf
[2] https://www.fenwickelliott.com/sites/default/files/Legal%20Briefing%2031-2008.pdf
[3] https://www.fenwickelliott.com/sites/default/files/Legal%20Briefing%2029-2008.pdf
[4] https://www.fenwickelliott.com/sites/default/files/Legal%20Briefing%2025-2008.pdf
[5] https://www.fenwickelliott.com/sites/default/files/Legal%20Briefing%2023-2008.pdf
[6] https://www.fenwickelliott.com/print/research-insight/newsletters/legal-briefing/contract-issues?page=15