I applied for a UK visit visa for my self and 3 children. 2 of my children have travelled with me to the uk previously. My youngest has not. We did our biometrics on the 20th June 2019. On the 10th July 2019 i got an email that the passport for myself and 2 other kids were ready. Today is the 26th of July and the passport for my 3 year old still hasn't been returned. I have sent email and called and got a response that the case has been escalated. Tickets have already been bought for the 6th August. I want to shift the the travel date by 2 weeks but is there any guarantee the passport will be out by then or should I just cancel.ynw whole trip
There is no guarantee that the remaining passport will be returned by your travel date (nor indeed does the email you’ve received guarantee that the other visas have been approved - see for example What does this mean? "Your UK visa application has been issued")
The UK specifically advises applicants not to make travel reservations until the visa decision is known. Flight and hotel booking documents are therefore not required when submitting the application (unless you’re applying for a transit visa). See Section 4 https://www.gov.uk/government/publications/visitor-visa-guide-to-supporting-documents/guide-to-supporting-documents-visiting-the-uk
It’s up to you whether you hang on and hope to receive all the decisions in time for the original travel date, postpone the trip, or cancel it until you know the application outcomes.