contract-law england-and-wales
Why couldn&#39;t the Ministry of Defence fetter its public law powers by promising not to transfer a SAS soldier?
<p><a href="https://www.amazon.co.uk/OSullivan-Hilliards-Law-Contract-Janet/dp/0198807821/ref=dp_ob_title_bk" rel="nofollow noreferrer"><em>O'Sullivan &amp; Hilliard's The Law of Contract</em></a> (2018 8 ed). p. 98.</p>
<blockquote>
<p><a href="https://i.stack.imgur.com/qcqds.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qcqds.jpg" alt="enter image description here" /></a></p>
</blockquote>
<p>The red underlines fit para. 31 of the <a href="http://www.bailii.org/uk/cases/UKPC/2003/22.html" rel="nofollow noreferrer">judgment</a>:</p>
<blockquote>
<ol start="31">
<li>In the present case the price for which R's promise was bought was the forbearance of the MOD to exercise its power to return him to unit. It could not be a promise that he would not be returned to unit, because, as their Lordships have already observed, the Crown was entitled to move him to another regiment and <strong>could not fetter its discretion by a contract having effect in private law [emboldening mine]</strong>. Whether there were any circumstances in which it could have created a legitimate expectation giving rise to rights against the Crown in public law is a matter which their Lordships need not discuss. But the actual forbearance was in their Lordships' opinion sufficient consideration to support the contract. In <em>Alliance Bank Ltd v Broom</em> (1864) 2 Dr &amp; Sm 289, 292 the bank demanded security for its loan in circumstances in which, as Sir Richard Kindersley V-C said, it would otherwise have enforced payment. It made no promise not to demand payment but:</li>
</ol>
<blockquote>
<p>&quot;the [bank] did in effect give, and the defendant received, the benefit of some degree of forbearance; not, indeed, for any definite time, but, at all events, some extent of forbearance.&quot;</p>
</blockquote>
</blockquote>

<p>The Ministry of Defence offered, as consideration, to agree not to transfer the individual, R.</p>

<p>It was held by the Privy Council, however, that the Ministry of Defence is not allowed to fetter (i.e limit) its own powers in such a way. It, as a statutory body, was given these powers and apparently these powers are absolute.</p>

<p>Therefore the consideration was invalid. And the contract would be void for lack of consideration.</p>
