EB (Kosovo) v Secretary of State for the Home Department [2008] UKHL 41, [2008] All ER (D) 334 (Jun)
There is no specified period within which an immigration decision must be made. It does not, however, follow that delay in the decision-making process is necessarily irrelevant to the decision.
The applicant may, during the period of any delay, develop closer personal and social ties and establish deeper roots in the community than he could have shown earlier.
Any relationship into which the applicant has entered will lose its sense of impermanence and the expectation will grow that if the authorities had intended to remove the applicant they would have taken steps to do so, thus affecting the proportionality of removal.
Delay may also be relevant if it is shown to be the result of a dysfunctional system which yields unpredictable, inconsistent and unfair outcomes.