Bargaining Power

observations:
Both employer and employee can enjoy a bargaining power at different points of time. This bargaining power can be a result of any of the following:
1. The prevailing market conditions (as already pointed by sushma)
2. The knowledge and experience of the employee.
3. The employment contract (as in this case)
4. The power of unions in the economy.
5. The substitutability of labour by capital in the economy or feasibility of outsourcing.
6. Support of government to the labour.

The first two has been rightly explained by Sushma. I would like to focus on the rest.
1. The employment contract: As highlighted by this case, the bargaining power of Darell hair was mainly because of the employment contract. He was supposed to retire in March 2008 but was asked to resign in 2006. So, in case he does not resign, ICC cannot fire him. In case it does, legal action can be taken against it and the case would strongly be in favour of Darell Hair. Similarly, an organisation can also enjoy this bargaining power arising from any crucial clause of the employment contract.
2. The power of unions in the economy: If the power of unions in the economy is very high, then the employee has the bargaining power. Any wrong move by the company can have undesirable consequence like strikes, shut down etc.
3. The substitutability of labour by capital or feasibility of outsourcing: If it is possible for the organization (depending upon employment contract etc), the organization may substitute highly demanding labour with capital or may even outsource to other countries where labour situations are favourable. In such cases, employer enjoys a bargaining power. But again, the knowledge and skill set of the employees play an important role. If the employee is highly qualified and experienced such that it is not feasible for the organisation to replace him then this power vests with the employee.
4. Support of the government to the labour: If the focus of the government in an economy is to employment or safeguarding the interest of labour and/or the position of government is highly dependent on labour (as in when elections are near etc), then the bargaining power of employee increases. Example: Jet airways and firing and re-hiring of 1100 employees.
Yes, I may be able to make a similar non- negotiable offer if my employment contract or any other condition (as above) allows me to.
If I receive a similar non-negotiable offer from any of my employees then I would do the following:
1. Check the employment contract to determine the veracity of the stated period of employment.
2. Check employment contract for any statements/clauses that specify the conditions under which I can fire the employee or terminate the contract. If found relevant to the current situation, I will enforce them.
3. Consult my lawyer for any situation in which I can make the case favourable for me if I do not accept the offer.
4. If I can do nothing then I will accept the offer but make the working conditions such that he will voluntarily resign.