ROYAL Bank of Scotland (RBS) boss Stephen Hester is facing calls to sell off one of the crown jewels in its empire, corporate broking house Hoare Govett, amid concerns new rules on bonuses at the group will irreparably damage the bank&rsquo;s competitiveness.<br /><br />Rival City bankers last night claimed the future of RBS&rsquo;s investment banking business is so perilous that Hester will have to embark on a&nbsp; break up in order to realise its full value. They said splitting up and selling off some of its investment banking operations might be the only option, starting with Hoare Govett, which RBS inherited during its disastrous takeover of Dutch bank ABN Amro before the financial meltdown.<br /><br />&ldquo;Hoare Govett is the obvious starting point for a sell-off of investment banking assets,&rdquo; said one banker. &ldquo;It&rsquo;s not tied into anything else and will suffer hugely if it is unable to offer competitive remuneration. Hester should get rid of it before it starts to wither on the vine.&rdquo;<br /><br />The stark warning from the City comes just days after the government dealt a crippling blow to the bank by placing a blanket ban on paying cash bonuses to high earners, a move the City feels will spark a mass exodus of RBS&rsquo;s top talent because of uncertainty over the future of the business.<br /><br />An RBS spokeswoman said Hoare Govett is &ldquo;core&rdquo; to the bank&rsquo;s operations. Hester, who is grappling with the trade-off between complying with government limitations on remuneration and remaining competitive, said earlier this week that the bank is &ldquo;straddling a difficult and unenviable line but one that we need to straddle&rdquo;. Hoare Govett, which counts a string of FTSE 100 firms as clients, including BAE Systems, Imperial Tobacco, GlaxoSmithKline and Cable &amp; Wireless, has long been the target of rivals who view it as a &ldquo;prized possession&rdquo;.<br />