i'm just a law student, so don't like rely on this or anything, especially because I think your agent friend will know the law here a lot better than me, but basically the situation is:
if there is any ambiguity in the contract about whether subletting is allowed or not, you can sublet. to the point that if the contract says you can't sublet (full stop), you can still sublet part of it (to get around this the contract has to say "in whole or in part")
if you're not allowed to sublet, and the landlord finds out, see if you can get him to accept rent after discovering this. If he's dumb enough to do that, he's affirmed the change in contract.
chances are, the clause will say that there is no subletting without the landlord's consent. If this is what the contract says, and he isn't giving consent, this has to be reasonable - i.e., for a fair and substantial reason. He does have to give a good reason.
if none of this applies and you get busted, you could theoretically, maybe, all be kicked out though this is well unlikely
i'm just a law student, so don't like rely on this or anything, especially because I think your agent friend will know the law here a lot better than me, but basically the situation is:
if there is any ambiguity in the contract about whether subletting is allowed or not, you can sublet. to the point that if the contract says you can't sublet (full stop), you can still sublet part of it (to get around this the contract has to say "in whole or in part")
if you're not allowed to sublet, and the landlord finds out, see if you can get him to accept rent after discovering this. If he's dumb enough to do that, he's affirmed the change in contract.
chances are, the clause will say that there is no subletting without the landlord's consent. If this is what the contract says, and he isn't giving consent, this has to be reasonable - i.e., for a fair and substantial reason. He does have to give a good reason.
if none of this applies and you get busted, you could theoretically, maybe, all be kicked out though this is well unlikely